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  • richardmitnick 2:24 pm on October 6, 2022 Permalink | Reply
    Tags: "Brigham Young University scientists collaborate with astronomers around the world to understand distant galaxy", Astronomy, , , Brigham Young University,   

    From Brigham Young University : “Brigham Young University scientists collaborate with astronomers around the world to understand distant galaxy” 

    From Brigham Young University

    10.4.22
    Tyler Stahle

    2
    Artistic rendering of the BL Lac jet with a spiral magnetic field. Photo by Iris Nieh.

    A team of 86 scientists from 13 countries recently carried out extensive high-time resolution optical monitoring of a distant active galaxy, BL Lacertae (BL Lac). Mike Joner, BYU research professor of physics and astronomy, was one of the astronomers contributing to the project.

    Dr. Joner and BYU undergraduate student Gilvan Apolonio secured over 200 observations of the galaxy using the 0.9-meter reflecting telescope at the BYU West Mountain Observatory. Their measurements were combined with observations made by other scientists around the world in a collaboration known as the Whole Earth Blazar Telescope (WEBT). The WEBT network makes it possible to monitor objects around the clock from different locations during times of high variability.

    Using the WEBT observations made in the summer of 2020, astronomers discovered surprisingly rapid oscillations of brightness in the central jet of the galaxy BL Lac. The scientists attribute these cycles of brightness change to twists in the jet’s magnetic field. Their study was recently published in the scientific journal Nature [below].

    BYU’s West Mountain Observatory was one of 37 ground-based telescopes throughout the world monitoring the optical variations of BL Lac – an active galaxy classified as a blazar that is roughly 1 billion light years away. Joner and Apolonio alternated working different groups of nights at the observatory throughout the spring and summer of 2020 – a task that was extra burdensome during the height of the pandemic. This atypical work schedule was necessary since observations were needed on every clear night and there were no other trained student observers remaining in the Provo area.

    An analysis of the high-cadence optical observations was critical to understanding the high-energy observations from the space-based Fermi Gamma-Ray Telescope.

    “You need to combine data from high-energy space observatories with optical ground-based monitoring data. The billion-dollar space telescopes that are used on projects like this often need to compare results with optical ground-based observations,” said Joner. “Correlating what was seen in the high energy observations with the ground-based light curves helped confirm the rapid periodic oscillations that were observed in the high-energy data from space.”

    Although he’s an established expert in astrophysical research, Joner says he continues to be amazed at the level of detail scientists are capturing through such observations. And he’s grateful for the chance to explore the far reaches of the cosmos with his students at BYU.

    “On a galactic scale, the central jet of a blazar is quite small. It is amazing to be able to see the variations of the jet so clearly. The variability of the jet is easily seen even though it is combined with the light from the hundreds of billions of stars in the host galaxy,” he said.

    “It is noteworthy that in this age of giant telescopes and space-based research, it is still necessary to rely on modest sized and well-equipped facilities like we have available at BYU to explore the unknown reaches of the Universe.”

    Boston University doctoral student Melissa Hallum, a BYU graduate and former student of Dr. Joner’s, was also a co-author of the paper.

    Science paper:
    Nature

    See the full article here.

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    Brigham Young University is a private research university in Provo, Utah. It was founded in 1875 by religious leader Brigham Young, and is sponsored by The Church of Jesus Christ of Latter-day Saints (LDS Church).

    Brigham Young University offers a variety of academic programs, including liberal arts, engineering, agriculture, management, physical and mathematical sciences, nursing, and law. It has 186 undergraduate majors, 64 master’s programs, and 26 doctoral programs. It is broadly organized into 11 colleges or schools at its main Provo campus, with certain colleges and divisions defining their own admission standards. The university also administers two satellite campuses, one in Jerusalem and one in Salt Lake City, while its parent organization the Church Educational System (CES) sponsors sister schools in Hawaii and Idaho. The university is accredited by the Northwest Commission on Colleges and Universities.

    Almost all Brigham Young University students are members of the LDS Church. Students attending BYU agree to follow an honor code, which mandates behavior in line with teachings of the church, such as academic honesty, adherence to dress and grooming standards, abstinence from extramarital sex, from same-sex romantic behavior, and from the consumption of drugs and alcohol. Undergraduate students are also required to complete curriculum in LDS religious education for graduation regardless of their course of study. Due in part to the church’s emphasis on missionary service, nearly 50% of BYU students have lived outside the United States, 65% speak a second language, and 63 languages are taught at the university regularly.

    BYU’s athletic teams compete in Division I of the NCAA and are collectively known as the BYU Cougars. Their football team is a D1 Independent, while their other sports teams compete in either the West Coast Conference or Mountain Pacific Sports Federation. BYU’s sports teams have won a total of 12 NCAA championships and 26 non-NCAA championships. On September 10, 2021, BYU formally accepted an invitation to the Big 12 Conference and will start participating in the conference in the 2023–24 school year.

    According to the National Science Foundation, Brigham Young University spent $40.7 million on research and development in 2018. Scientists associated with Brigham Young University have created some notable inventions. Philo T. Farnsworth, inventor and pioneer of the electronic television, began college at Brigham Young University, and later returned to do fusion research, receiving an honorary degree from the university in 1967. Alumnus Harvey Fletcher, inventor of stereophonic sound, went on to carry out the now famous oil-drop experiment with Robert Millikan, and was later Founding Dean of the Brigham Young University College of Engineering. H. Tracy Hall, inventor of the man-made diamond, left General Electric in 1955 and became a full professor of chemistry and Director of Research at Brigham Young University. While there, he invented a new type of diamond press, the tetrahedral press. In student achievements, Brigham Young University Ad Lab teams won both the 2007 and 2008 L’Oréal National Brandstorm Competition, and students developed the Magnetic Lasso algorithm found in Adobe Photoshop. In prestigious scholarships, Brigham Young University has produced 10 Rhodes Scholars, four Gates Scholars in the last six years, and in the last decade has claimed 41 Fulbright scholars and 3 Jack Kent Cooke scholars.

     
  • richardmitnick 12:39 pm on October 5, 2022 Permalink | Reply
    Tags: , Astronomy, , , , , "A Stellar ‘Light Switch’ Orbiting a Black Hole", The event was called AT2018fyk and further analysis found that the emission was coming from the nucleus of a galaxy named LCRS B224721.6−450748., 600 days after the initial discovery there was a sharp decrease in the brightness of the X-ray and UV emission., 600 days after the dimming began the ‘light switch’ was flipped and the X-ray and UV emission from AT2018fyk have returned to close to pre-dimming levels.   

    From Astrobites : “A Stellar ‘Light Switch’ Orbiting a Black Hole” 

    Astrobites bloc

    From Astrobites

    10.5.22
    Evan Lewis

    Title: The rebrightening of AT2018fyk as a repeating partial tidal disruption event

    Authors: T. Wevers, E.R. Coughlin, D.R. Pasham, M. Guolo, Y. Sun, S. Wen, P.G. Jonker, A. Zabludoff, A. Malyali, R. Arcodia, Z. Liu, A. Merloni, A. Rau, I. Grotova, P. Short, Z. Cao

    First Author’s Institution: The European Southern Observatory [La Observatorio Europeo Austral] [Observatoire européen austral][Europaiche Sûdsternwarte] (EU)(CL)
    Status: Submitted to ApJ Letters [open access]

    Out in the center of a distant galaxy, a star is being torn apart as it circles the drain around an enormous black hole! Today’s paper reports on the re-emergence of X-ray and UV emission from a star orbiting a supermassive black hole (SMBH). After being discovered, this emission suddenly flicked off and stayed undetectable for ~600 days, before it quickly returned like a light switch being turned back on after a blackout– making this a very dynamic system to study.

    In 2018, optical emission from the star was discovered by the All-Sky Automated Survey for Supernovae (ASASSN), a supernova search using 24 telescopes around the world which can see objects 50,000 times dimmer than we can see with our naked eyes!

    The event was called AT2018fyk and further analysis found that the emission was coming from the nucleus of a galaxy named LCRS B224721.6−450748. These super catchy and memorable names are thanks to astronomers using astrometric coordinates and dates of discovery to name new objects, since there are too many in the sky to give each a unique name! But 600 days after the initial discovery there was a sharp decrease in the brightness of the X-ray and UV emission, with the X-ray emission plummeting to less than 1/6,000th of its original brightness. For 600 days, this dimming persisted, suggesting that the star had been torn apart by the gravitational pull of the black hole, and all of the stellar material had fallen onto the surface of the black hole, leaving nothing behind. This is known as a tidal disruption event (TDE), since the tidal forces (yes, the same ones that cause the ocean tides on Earth!) rip the star apart.

    However, today’s authors report that 600 days after the dimming began the ‘light switch’ was flipped and the X-ray and UV emission from AT2018fyk have returned to close to pre-dimming levels. In most tidal disruptions, the star is totally torn apart and the emission slowly fades, never to return– so their hypothesis is that this event was only a partial TDE, where the core of the star remained intact while only the outer layers were stripped away.

    1
    Figure 1: Cartoons illustrating the evolution of the star/SMBH system over time. The binary system is torn apart in panels a) and b), the stellar material begins to fall onto the black hole in panel c), the star moves away from the black hole in panel e), and the tidal disruption begins once again in panel f). Figure 3 from today’s paper.

    Figure 1 shows a schematic which illustrates the key phases of AT2018fyk’s history. The origins of this system are unique- given the previously estimated SMBH mass, a star should theoretically take at least a few thousand years to make one full orbit around the central black hole– way longer than the timescales of a few years that we’re seeing! But, if the star was originally part of a binary system, the black hole can disrupt the binary, pulling one star into an orbit around the black hole while the other star is shot at extremely high speeds away from the galaxy. Panels a) and b) of Figure 1 show this process, with the yellow dot representing the star’s ex-binary companion (now called a hypervelocity star) which is flung off into space.

    Panel c), at t=0, matches up with the initial discovery of the system, with material falling onto the surface of the supermassive black hole and getting heated up, which creates X-rays. This process is called accretion, or stellar fallback. Panel e), at t=600 days after discovery, shows that at this point the core of the star has moved farther away from the SMBH, and the stellar material remains gravitationally attracted to the stellar core, so it has stopped falling onto the SMBH– this is the point at which the X-ray and UV emission got much dimmer. At t=1200 days (the focus of this paper), what remains of the star has moved back into the region where the outer material of the star will be pulled onto the SMBH, and the emission ‘turns on’ once again.

    2
    Figure 2- the light curve of the stellar/SMBH system over time, since its discovery. Both the UV (green diamond; from Swift) and X-ray (black, from Swift/XMM-Newton/Chandra/eROSITA) light curves are shown. The x-axis is measured in days, with t=0 equal to the discovery of the system. Top left panel of Figure 1 from today’s paper.

    Figure 2 shows the light curve, or the luminosity of the emission over time, in the UV (green) and X-ray (black) wavelength ranges over the course of the observational history of AT2018fyk. Letters A-D represent the first 600 days of bright emission: at first, the UV emission is brighter (higher up on the y-axis) than the X-ray emission, but they switch around letter C. Why do we observe this behavior? At early times, the gas surrounding SMBH will be optically thick, but when the star moves away and the rate of fallback declines, the gas is able to expand and cool, becoming more optically thin (puffier) so it’s easier to see through to the hot inner region of the system, leading to brighter X-ray emission. At letter E, the dimming period begins as the star moves away from the SMBH, and the emission brightness drops sharply into its “quiescent” state. Finally, at letter F, the bright emission returns at similar luminosity levels to before, implying that the same star has orbited back around to a point where material is falling onto the SMBH.

    The authors predict that there will be another sharp brightness decline in August 2023 and, if the star survives this second encounter, a third episode of re-brightening should begin around March 2025. This gives astronomers an exciting prediction to look forward to confirming or denying, as we continue to learn about exotic systems like this!

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.


    Stem Education Coalition

    What do we do?

    Astrobites is a daily astrophysical literature journal written by graduate students in astronomy. Our goal is to present one interesting paper per day in a brief format that is accessible to undergraduate students in the physical sciences who are interested in active research.
    Why read Astrobites?

    Reading a technical paper from an unfamiliar subfield is intimidating. It may not be obvious how the techniques used by the researchers really work or what role the new research plays in answering the bigger questions motivating that field, not to mention the obscure jargon! For most people, it takes years for scientific papers to become meaningful.

    Our goal is to solve this problem, one paper at a time. In 5 minutes a day reading Astrobites, you should not only learn about one interesting piece of current work, but also get a peek at the broader picture of research in a new area of astronomy.

     
  • richardmitnick 11:18 am on October 5, 2022 Permalink | Reply
    Tags: "Astronomers find a 'cataclysmic' pair of stars with the shortest orbit yet", Astronomy, , , , Scientists caught this system in the act of switching from hydrogen to helium accretion., , , The newly discovered system tagged ZTF J1813+4251, This is the first time such a transitioning system has been observed directly.,   

    From The Massachusetts Institute of Technology And The Harvard-Smithsonian Center for Astrophysics: “Astronomers find a ‘cataclysmic’ pair of stars with the shortest orbit yet” 

    From The Massachusetts Institute of Technology

    And

    The Harvard-Smithsonian Center for Astrophysics

    10.5.22
    Jennifer Chu

    1
    An artist’s illustration shows a white dwarf (right) circling a larger, sun-like star (left) in an ultra-short orbit, forming a “cataclysmic” binary system. Credit: M.Weiss/Center for Astrophysics | Harvard & Smithsonian.

    Nearly half the stars in our galaxy are solitary like the sun. The other half comprises stars that circle other stars, in pairs and multiples, with orbits so tight that some stellar systems could fit between Earth and the moon.

    Astronomers at MIT and elsewhere have now discovered a stellar binary, or pair of stars, with an extremely short orbit, appearing to circle each other every 51 minutes. The system seems to be one of a rare class of binaries known as a “cataclysmic variable,” in which a star similar to our sun orbits tightly around a white dwarf — a hot, dense core of a burned-out star.

    A cataclysmic variable occurs when the two stars draw close, over billions of years, causing the white dwarf to start accreting, or eating material away from its partner star. This process can give off enormous, variable flashes of light that, centuries ago, astronomers assumed to be a result of some unknown cataclysm.

    The newly discovered system, which the team has tagged ZTF J1813+4251, is a cataclysmic variable with the shortest orbit detected to date. Unlike other such systems observed in the past, the astronomers caught this cataclysmic variable as the stars eclipsed each other multiple times, allowing the team to precisely measure properties of each star.

    With these measurements, the researchers ran simulations of what the system is likely doing today and how it should evolve over the next hundreds of millions of years. They conclude that the stars are currently in transition, and that the sun-like star has been circling and “donating” much of its hydrogen atmosphere to the voracious white dwarf. The sun-like star will eventually be stripped down to a mostly dense, helium-rich core. In another 70 million years, the stars will migrate even closer together, with an ultrashort orbit reaching just 18 minutes, before they begin to expand and drift apart.

    Decades ago, researchers at MIT and elsewhere predicted that such cataclysmic variables should transition to ultrashort orbits. This is the first time such a transitioning system has been observed directly.

    “This is a rare case where we caught one of these systems in the act of switching from hydrogen to helium accretion,” says Kevin Burdge, a Pappalardo Fellow in MIT’s Department of Physics. “People predicted these objects should transition to ultrashort orbits, and it was debated for a long time whether they could get short enough to emit detectable gravitational waves. This discovery puts that to rest.”​

    Burdge and colleagues report their discovery today in Nature [below]. The study’s co-authors include collaborators from multiple institutions, including the Harvard and Smithsonian Center for Astrophysics.

    Sky search

    The astronomers discovered the new system within a vast catalog of stars, observed by the Zwicky Transient Facility (ZTF), a survey that uses a camera attached to a telescope at the Palomar Observatory in California to take high-resolution pictures of wide swaths of the sky.

    The survey has taken more than 1,000 images of each of the more than 1 billion stars in the sky, recording each star’s changing brightness over days, months, and years.

    Burdge combed through the catalog, looking for signals of systems with ultrashort orbits, the dynamics of which can be so extreme that they should give off dramatic bursts of light and emit gravitational waves.

    “Gravitational waves are allowing us to study the universe in a totally new way,” says Burdge, who is searching the sky for new gravitational-wave sources.

    For this new study, Burdge looked through the ZTF data for stars that appeared to flash repeatedly, with a period of less than an hour — a frequency that typically signals a system of at least two closely orbiting objects, with one crossing the other and briefly blocking its light.

    He used an algorithm to weed through over 1 billion stars, each of which was recorded in more than 1,000 images. The algorithm sifted out about 1 million stars that appeared to flash every hour or so. Among these, Burdge then looked by eye for signals of particular interest. His search zeroed in on ZTF J1813+4251 — a system that resides about 3,000 light years from Earth, in the Hercules constellation.

    “This thing popped up, where I saw an eclipse happening every 51 minutes, and I said, OK, this is definitely a binary,” Burdge recalls.

    A dense core

    He and his colleagues further focused on the system using the W.M. Keck Observatory in Hawai’i and the Gran Telescopio Canarias in Spain.

    They found that the system was exceptionally “clean,” meaning they could clearly see its light change with each eclipse. With such clarity, they were able to precisely measure each object’s mass and radius, as well as their orbital period.

    They found that the first object was likely a white dwarf, at 1/100th the size of the sun and about half its mass. The second object was a sun-like star near the end of its life, at a tenth the size and mass of the sun (about the size of Jupiter). The stars also appeared to orbit each other every 51 minutes.

    Yet, something didn’t quite add up.

    “This one star looked like the sun, but the sun can’t fit into an orbit shorter than eight hours — what’s up here?” Burdge says.

    He soon hit upon an explanation: Nearly 30 years ago, researchers including MIT Professor Emeritus Saul Rappaport had predicted that ultrashort-orbit systems should exist as cataclysmic variables. As the white dwarf eats orbits the sun-like star and eats away its light hydrogen, the sun-like star should burn out, leaving a core of helium — an element that is more dense than hydrogen, and heavy enough to keep the dead star in a tight, ultrashort orbit.

    Burdge realized that ZTF J1813+4251 was likely a cataclysmic variable, in the act of transitioning from a hydrogen- to helium-rich body. The discovery both confirms the predictions made by Rappaport and others, and also stands as the shortest orbit cataclysmic variable detected to date.

    “This is a special system,” Burdge says. “We got doubly lucky to find a system that answers a big open question, and is one of the most beautifully behaved cataclysmic variables known.”

    This research was supported, in part, by the European Research Council.

    Science paper:
    Nature

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings
    Please help promote STEM in your local schools.

    Stem Education Coalition

    The The Harvard-Smithsonian Center for Astrophysics combines the resources and research facilities of the Harvard College Observatory and the Smithsonian Astrophysical Observatory under a single director to pursue studies of those basic physical processes that determine the nature and evolution of the universe. The Smithsonian Astrophysical Observatory is a bureau of the Smithsonian Institution, founded in 1890. The Harvard College Observatory, founded in 1839, is a research institution of the Faculty of Arts and Sciences, Harvard University, and provides facilities and substantial other support for teaching activities of the Department of Astronomy.

    Founded in 1973 and headquartered in Cambridge, Massachusetts, the CfA leads a broad program of research in astronomy, astrophysics, Earth and space sciences, as well as science education. The CfA either leads or participates in the development and operations of more than fifteen ground- and space-based astronomical research observatories across the electromagnetic spectrum, including the forthcoming Giant Magellan Telescope(CL) and the Chandra X-ray Observatory, one of NASA’s Great Observatories.

    GMT Giant Magellan Telescope(CL) 21 meters, to be at the Carnegie Institution for Science’s NSF NOIRLab NOAO Las Campanas Observatory(CL) some 115 km (71 mi) north-northeast of La Serena, Chile, over 2,500 m (8,200 ft) high.

    National Aeronautics and Space Administration Chandra X-ray telescope.

    Hosting more than 850 scientists, engineers, and support staff, the CfA is among the largest astronomical research institutes in the world. Its projects have included Nobel Prize-winning advances in cosmology and high energy astrophysics, the discovery of many exoplanets, and the first image of a black hole. The CfA also serves a major role in the global astrophysics research community: the CfA’s Astrophysics Data System, for example, has been universally adopted as the world’s online database of astronomy and physics papers. Known for most of its history as the “Harvard-Smithsonian Center for Astrophysics”, the CfA rebranded in 2018 to its current name in an effort to reflect its unique status as a joint collaboration between Harvard University and the Smithsonian Institution. The CfA’s current Director (since 2004) is Charles R. Alcock, who succeeds Irwin I. Shapiro (Director from 1982 to 2004) and George B. Field (Director from 1973 to 1982).

    The Center for Astrophysics | Harvard & Smithsonian is not formally an independent legal organization, but rather an institutional entity operated under a Memorandum of Understanding between Harvard University and the Smithsonian Institution. This collaboration was formalized on July 1, 1973, with the goal of coordinating the related research activities of the Harvard College Observatory (HCO) and the Smithsonian Astrophysical Observatory (SAO) under the leadership of a single Director, and housed within the same complex of buildings on the Harvard campus in Cambridge, Massachusetts. The CfA’s history is therefore also that of the two fully independent organizations that comprise it. With a combined lifetime of more than 300 years, HCO and SAO have been host to major milestones in astronomical history that predate the CfA’s founding.

    History of the Smithsonian Astrophysical Observatory (SAO)

    Samuel Pierpont Langley, the third Secretary of the Smithsonian, founded the Smithsonian Astrophysical Observatory on the south yard of the Smithsonian Castle (on the U.S. National Mall) on March 1,1890. The Astrophysical Observatory’s initial, primary purpose was to “record the amount and character of the Sun’s heat”. Charles Greeley Abbot was named SAO’s first director, and the observatory operated solar telescopes to take daily measurements of the Sun’s intensity in different regions of the optical electromagnetic spectrum. In doing so, the observatory enabled Abbot to make critical refinements to the Solar constant, as well as to serendipitously discover Solar variability. It is likely that SAO’s early history as a solar observatory was part of the inspiration behind the Smithsonian’s “sunburst” logo, designed in 1965 by Crimilda Pontes.

    In 1955, the scientific headquarters of SAO moved from Washington, D.C. to Cambridge, Massachusetts to affiliate with the Harvard College Observatory (HCO). Fred Lawrence Whipple, then the chairman of the Harvard Astronomy Department, was named the new director of SAO. The collaborative relationship between SAO and HCO therefore predates the official creation of the CfA by 18 years. SAO’s move to Harvard’s campus also resulted in a rapid expansion of its research program. Following the launch of Sputnik (the world’s first human-made satellite) in 1957, SAO accepted a national challenge to create a worldwide satellite-tracking network, collaborating with the United States Air Force on Project Space Track.

    With the creation of National Aeronautics and Space Administration the following year and throughout the space race, SAO led major efforts in the development of orbiting observatories and large ground-based telescopes, laboratory and theoretical astrophysics, as well as the application of computers to astrophysical problems.

    History of Harvard College Observatory (HCO)

    Partly in response to renewed public interest in astronomy following the 1835 return of Halley’s Comet, the Harvard College Observatory was founded in 1839, when the Harvard Corporation appointed William Cranch Bond as an “Astronomical Observer to the University”. For its first four years of operation, the observatory was situated at the Dana-Palmer House (where Bond also resided) near Harvard Yard, and consisted of little more than three small telescopes and an astronomical clock. In his 1840 book recounting the history of the college, then Harvard President Josiah Quincy III noted that “…there is wanted a reflecting telescope equatorially mounted…”. This telescope, the 15-inch “Great Refractor”, opened seven years later (in 1847) at the top of Observatory Hill in Cambridge (where it still exists today, housed in the oldest of the CfA’s complex of buildings). The telescope was the largest in the United States from 1847 until 1867. William Bond and pioneer photographer John Adams Whipple used the Great Refractor to produce the first clear Daguerrotypes of the Moon (winning them an award at the 1851 Great Exhibition in London). Bond and his son, George Phillips Bond (the second Director of HCO), used it to discover Saturn’s 8th moon, Hyperion (which was also independently discovered by William Lassell).

    Under the directorship of Edward Charles Pickering from 1877 to 1919, the observatory became the world’s major producer of stellar spectra and magnitudes, established an observing station in Peru, and applied mass-production methods to the analysis of data. It was during this time that HCO became host to a series of major discoveries in astronomical history, powered by the Observatory’s so-called “Computers” (women hired by Pickering as skilled workers to process astronomical data). These “Computers” included Williamina Fleming; Annie Jump Cannon; Henrietta Swan Leavitt; Florence Cushman; and Antonia Maury, all widely recognized today as major figures in scientific history. Henrietta Swan Leavitt, for example, discovered the so-called period-luminosity relation for Classical Cepheid variable stars, establishing the first major “standard candle” with which to measure the distance to galaxies. Now called “Leavitt’s Law”, the discovery is regarded as one of the most foundational and important in the history of astronomy; astronomers like Edwin Hubble, for example, would later use Leavitt’s Law to establish that the Universe is expanding, the primary piece of evidence for the Big Bang model.

    Upon Pickering’s retirement in 1921, the Directorship of HCO fell to Harlow Shapley (a major participant in the so-called “Great Debate” of 1920). This era of the observatory was made famous by the work of Cecelia Payne-Gaposchkin, who became the first woman to earn a Ph.D. in astronomy from Radcliffe College (a short walk from the Observatory). Payne-Gapochkin’s 1925 thesis proposed that stars were composed primarily of hydrogen and helium, an idea thought ridiculous at the time. Between Shapley’s tenure and the formation of the CfA, the observatory was directed by Donald H. Menzel and then Leo Goldberg, both of whom maintained widely recognized programs in solar and stellar astrophysics. Menzel played a major role in encouraging the Smithsonian Astrophysical Observatory to move to Cambridge and collaborate more closely with HCO.

    Joint history as the Center for Astrophysics (CfA)

    The collaborative foundation for what would ultimately give rise to the Center for Astrophysics began with SAO’s move to Cambridge in 1955. Fred Whipple, who was already chair of the Harvard Astronomy Department (housed within HCO since 1931), was named SAO’s new director at the start of this new era; an early test of the model for a unified Directorship across HCO and SAO. The following 18 years would see the two independent entities merge ever closer together, operating effectively (but informally) as one large research center.

    This joint relationship was formalized as the new Harvard–Smithsonian Center for Astrophysics on July 1, 1973. George B. Field, then affiliated with University of California- Berkeley, was appointed as its first Director. That same year, a new astronomical journal, the CfA Preprint Series was created, and a CfA/SAO instrument flying aboard Skylab discovered coronal holes on the Sun. The founding of the CfA also coincided with the birth of X-ray astronomy as a new, major field that was largely dominated by CfA scientists in its early years. Riccardo Giacconi, regarded as the “father of X-ray astronomy”, founded the High Energy Astrophysics Division within the new CfA by moving most of his research group (then at American Sciences and Engineering) to SAO in 1973. That group would later go on to launch the Einstein Observatory (the first imaging X-ray telescope) in 1976, and ultimately lead the proposals and development of what would become the Chandra X-ray Observatory. Chandra, the second of NASA’s Great Observatories and still the most powerful X-ray telescope in history, continues operations today as part of the CfA’s Chandra X-ray Center. Giacconi would later win the 2002 Nobel Prize in Physics for his foundational work in X-ray astronomy.

    Shortly after the launch of the Einstein Observatory, the CfA’s Steven Weinberg won the 1979 Nobel Prize in Physics for his work on electroweak unification. The following decade saw the start of the landmark CfA Redshift Survey (the first attempt to map the large scale structure of the Universe), as well as the release of the Field Report, a highly influential Astronomy & Astrophysics Decadal Survey chaired by the outgoing CfA Director George Field. He would be replaced in 1982 by Irwin Shapiro, who during his tenure as Director (1982 to 2004) oversaw the expansion of the CfA’s observing facilities around the world.

    Harvard Smithsonian Center for Astrophysics Fred Lawrence Whipple Observatory located near Amado, Arizona on the slopes of Mount Hopkins, Altitude 2,606 m (8,550 ft)

    European Space Agency [La Agencia Espacial Europea] [Agence spatiale européenne] [Europäische Weltraumorganisation] (EU)/National Aeronautics and Space Administration SOHO satellite. Launched in 1995.

    National Aeronautics Space Agency NASA Kepler Space Telescope

    CfA-led discoveries throughout this period include canonical work on Supernova 1987A, the “CfA2 Great Wall” (then the largest known coherent structure in the Universe), the best-yet evidence for supermassive black holes, and the first convincing evidence for an extrasolar planet.

    The 1990s also saw the CfA unwittingly play a major role in the history of computer science and the internet: in 1990, SAO developed SAOImage, one of the world’s first X11-based applications made publicly available (its successor, DS9, remains the most widely used astronomical FITS image viewer worldwide). During this time, scientists at the CfA also began work on what would become the Astrophysics Data System (ADS), one of the world’s first online databases of research papers. By 1993, the ADS was running the first routine transatlantic queries between databases, a foundational aspect of the internet today.

    The CfA Today

    Research at the CfA

    Charles Alcock, known for a number of major works related to massive compact halo objects, was named the third director of the CfA in 2004. Today Alcock overseas one of the largest and most productive astronomical institutes in the world, with more than 850 staff and an annual budget in excess of $100M. The Harvard Department of Astronomy, housed within the CfA, maintains a continual complement of approximately 60 Ph.D. students, more than 100 postdoctoral researchers, and roughly 25 undergraduate majors in astronomy and astrophysics from Harvard College. SAO, meanwhile, hosts a long-running and highly rated REU Summer Intern program as well as many visiting graduate students. The CfA estimates that roughly 10% of the professional astrophysics community in the United States spent at least a portion of their career or education there.

    The CfA is either a lead or major partner in the operations of the Fred Lawrence Whipple Observatory, the Submillimeter Array, MMT Observatory, the South Pole Telescope, VERITAS, and a number of other smaller ground-based telescopes. The CfA’s 2019-2024 Strategic Plan includes the construction of the Giant Magellan Telescope as a driving priority for the Center.

    CFA Harvard Smithsonian Submillimeter Array on Mauna Kea, Hawaii, Altitude 4,205 m (13,796 ft).

    South Pole Telescope SPTPOL. The SPT collaboration is made up of over a dozen (mostly North American) institutions, including The University of Chicago ; The University of California-Berkeley ; Case Western Reserve University; Harvard/Smithsonian Astrophysical Observatory; The University of Colorado- Boulder; McGill (CA) University, The University of Illinois, Urbana-Champaign; The University of California- Davis; Ludwig Maximilians Universität München(DE); DOE’s Argonne National Laboratory; and The National Institute for Standards and Technology.

    Along with the Chandra X-ray Observatory, the CfA plays a central role in a number of space-based observing facilities, including the recently launched Parker Solar Probe, Kepler Space Telescope, the Solar Dynamics Observatory (SDO), and HINODE. The CfA, via the Smithsonian Astrophysical Observatory, recently played a major role in the Lynx X-ray Observatory, a NASA-Funded Large Mission Concept Study commissioned as part of the 2020 Decadal Survey on Astronomy and Astrophysics (“Astro2020”). If launched, Lynx would be the most powerful X-ray observatory constructed to date, enabling order-of-magnitude advances in capability over Chandra.

    [caption id="attachment_60988" align="alignnone" width="632"] NASA Parker Solar Probe Plus named to honor Pioneering Physicist Eugene Parker. The Johns Hopkins University Applied Physics Lab.

    National Aeronautics and Space Administration Solar Dynamics Observatory.

    Japan Aerospace Exploration Agency (JAXA) (国立研究開発法人宇宙航空研究開発機構] (JP)/National Aeronautics and Space Administration HINODE spacecraft.

    SAO is one of the 13 stakeholder institutes for the Event Horizon Telescope Board, and the CfA hosts its Array Operations Center. In 2019, the project revealed the first direct image of a black hole.

    Messier 87*, The first image of the event horizon of a black hole. This is the supermassive black hole at the center of the galaxy Messier 87. Image via The Event Horizon Telescope Collaboration released on 10 April 2019 via National Science Foundation.

    The result is widely regarded as a triumph not only of observational radio astronomy, but of its intersection with theoretical astrophysics. Union of the observational and theoretical subfields of astrophysics has been a major focus of the CfA since its founding.

    In 2018, the CfA rebranded, changing its official name to the “Center for Astrophysics | Harvard & Smithsonian” in an effort to reflect its unique status as a joint collaboration between Harvard University and the Smithsonian Institution. Today, the CfA receives roughly 70% of its funding from NASA, 22% from Smithsonian federal funds, and 4% from the National Science Foundation. The remaining 4% comes from contributors including the United States Department of Energy, the Annenberg Foundation, as well as other gifts and endowments.

    MIT Seal

    [caption id="attachment_116504" align="alignnone" width="632"] USPS “Forever” postage stamps celebrating Innovation at MIT.

    MIT Campus

    The Massachusetts Institute of Technology is a private land-grant research university in Cambridge, Massachusetts. The institute has an urban campus that extends more than a mile (1.6 km) alongside the Charles River. The institute also encompasses a number of major off-campus facilities such as the MIT Lincoln Laboratory , the MIT Bates Research and Engineering Center , and the Haystack Observatory , as well as affiliated laboratories such as the Broad Institute of MIT and Harvard and Whitehead Institute.

    Massachusettes Institute of Technology-Haystack Observatory Westford, Massachusetts, USA, Altitude 131 m (430 ft).

    Founded in 1861 in response to the increasing industrialization of the United States, Massachusetts Institute of Technology adopted a European polytechnic university model and stressed laboratory instruction in applied science and engineering. It has since played a key role in the development of many aspects of modern science, engineering, mathematics, and technology, and is widely known for its innovation and academic strength. It is frequently regarded as one of the most prestigious universities in the world.

    As of December 2020, 97 Nobel laureates, 26 Turing Award winners, and 8 Fields Medalists have been affiliated with MIT as alumni, faculty members, or researchers. In addition, 58 National Medal of Science recipients, 29 National Medals of Technology and Innovation recipients, 50 MacArthur Fellows, 80 Marshall Scholars, 3 Mitchell Scholars, 22 Schwarzman Scholars, 41 astronauts, and 16 Chief Scientists of the U.S. Air Force have been affiliated with The Massachusetts Institute of Technology. The university also has a strong entrepreneurial culture and MIT alumni have founded or co-founded many notable companies. Massachusetts Institute of Technology is a member of the Association of American Universities.

    Foundation and vision

    In 1859, a proposal was submitted to the Massachusetts General Court to use newly filled lands in Back Bay, Boston for a “Conservatory of Art and Science”, but the proposal failed. A charter for the incorporation of the Massachusetts Institute of Technology, proposed by William Barton Rogers, was signed by John Albion Andrew, the governor of Massachusetts, on April 10, 1861.

    Rogers, a professor from the University of Virginia , wanted to establish an institution to address rapid scientific and technological advances. He did not wish to found a professional school, but a combination with elements of both professional and liberal education, proposing that:

    “The true and only practicable object of a polytechnic school is, as I conceive, the teaching, not of the minute details and manipulations of the arts, which can be done only in the workshop, but the inculcation of those scientific principles which form the basis and explanation of them, and along with this, a full and methodical review of all their leading processes and operations in connection with physical laws.”

    The Rogers Plan reflected the German research university model, emphasizing an independent faculty engaged in research, as well as instruction oriented around seminars and laboratories.

    Early developments

    Two days after The Massachusetts Institute of Technology was chartered, the first battle of the Civil War broke out. After a long delay through the war years, MIT’s first classes were held in the Mercantile Building in Boston in 1865. The new institute was founded as part of the Morrill Land-Grant Colleges Act to fund institutions “to promote the liberal and practical education of the industrial classes” and was a land-grant school. In 1863 under the same act, the Commonwealth of Massachusetts founded the Massachusetts Agricultural College, which developed as the University of Massachusetts Amherst ). In 1866, the proceeds from land sales went toward new buildings in the Back Bay.

    The Massachusetts Institute of Technology was informally called “Boston Tech”. The institute adopted the European polytechnic university model and emphasized laboratory instruction from an early date. Despite chronic financial problems, the institute saw growth in the last two decades of the 19th century under President Francis Amasa Walker. Programs in electrical, chemical, marine, and sanitary engineering were introduced, new buildings were built, and the size of the student body increased to more than one thousand.

    The curriculum drifted to a vocational emphasis, with less focus on theoretical science. The fledgling school still suffered from chronic financial shortages which diverted the attention of the MIT leadership. During these “Boston Tech” years, Massachusetts Institute of Technology faculty and alumni rebuffed Harvard University president (and former MIT faculty) Charles W. Eliot’s repeated attempts to merge MIT with Harvard College’s Lawrence Scientific School. There would be at least six attempts to absorb MIT into Harvard. In its cramped Back Bay location, MIT could not afford to expand its overcrowded facilities, driving a desperate search for a new campus and funding. Eventually, the MIT Corporation approved a formal agreement to merge with Harvard, over the vehement objections of MIT faculty, students, and alumni. However, a 1917 decision by the Massachusetts Supreme Judicial Court effectively put an end to the merger scheme.

    In 1916, The Massachusetts Institute of Technology administration and the MIT charter crossed the Charles River on the ceremonial barge Bucentaur built for the occasion, to signify MIT’s move to a spacious new campus largely consisting of filled land on a one-mile-long (1.6 km) tract along the Cambridge side of the Charles River. The neoclassical “New Technology” campus was designed by William W. Bosworth and had been funded largely by anonymous donations from a mysterious “Mr. Smith”, starting in 1912. In January 1920, the donor was revealed to be the industrialist George Eastman of Rochester, New York, who had invented methods of film production and processing, and founded Eastman Kodak. Between 1912 and 1920, Eastman donated $20 million ($236.6 million in 2015 dollars) in cash and Kodak stock to MIT.

    Curricular reforms

    In the 1930s, President Karl Taylor Compton and Vice-President (effectively Provost) Vannevar Bush emphasized the importance of pure sciences like physics and chemistry and reduced the vocational practice required in shops and drafting studios. The Compton reforms “renewed confidence in the ability of the Institute to develop leadership in science as well as in engineering”. Unlike Ivy League schools, Massachusetts Institute of Technology catered more to middle-class families, and depended more on tuition than on endowments or grants for its funding. The school was elected to the Association of American Universities in 1934.

    Still, as late as 1949, the Lewis Committee lamented in its report on the state of education at The Massachusetts Institute of Technology that “the Institute is widely conceived as basically a vocational school”, a “partly unjustified” perception the committee sought to change. The report comprehensively reviewed the undergraduate curriculum, recommended offering a broader education, and warned against letting engineering and government-sponsored research detract from the sciences and humanities. The School of Humanities, Arts, and Social Sciences and the MIT Sloan School of Management were formed in 1950 to compete with the powerful Schools of Science and Engineering. Previously marginalized faculties in the areas of economics, management, political science, and linguistics emerged into cohesive and assertive departments by attracting respected professors and launching competitive graduate programs. The School of Humanities, Arts, and Social Sciences continued to develop under the successive terms of the more humanistically oriented presidents Howard W. Johnson and Jerome Wiesner between 1966 and 1980.

    The Massachusetts Institute of Technology‘s involvement in military science surged during World War II. In 1941, Vannevar Bush was appointed head of the federal Office of Scientific Research and Development and directed funding to only a select group of universities, including MIT. Engineers and scientists from across the country gathered at Massachusetts Institute of Technology ‘s Radiation Laboratory, established in 1940 to assist the British military in developing microwave radar. The work done there significantly affected both the war and subsequent research in the area. Other defense projects included gyroscope-based and other complex control systems for gunsight, bombsight, and inertial navigation under Charles Stark Draper’s Instrumentation Laboratory; the development of a digital computer for flight simulations under Project Whirlwind; and high-speed and high-altitude photography under Harold Edgerton. By the end of the war, The Massachusetts Institute of Technology became the nation’s largest wartime R&D contractor (attracting some criticism of Bush), employing nearly 4000 in the Radiation Laboratory alone and receiving in excess of $100 million ($1.2 billion in 2015 dollars) before 1946. Work on defense projects continued even after then. Post-war government-sponsored research at MIT included SAGE and guidance systems for ballistic missiles and Project Apollo.

    These activities affected The Massachusetts Institute of Technology profoundly. A 1949 report noted the lack of “any great slackening in the pace of life at the Institute” to match the return to peacetime, remembering the “academic tranquility of the prewar years”, though acknowledging the significant contributions of military research to the increased emphasis on graduate education and rapid growth of personnel and facilities. The faculty doubled and the graduate student body quintupled during the terms of Karl Taylor Compton, president of The Massachusetts Institute of Technology between 1930 and 1948; James Rhyne Killian, president from 1948 to 1957; and Julius Adams Stratton, chancellor from 1952 to 1957, whose institution-building strategies shaped the expanding university. By the 1950s, The Massachusetts Institute of Technology no longer simply benefited the industries with which it had worked for three decades, and it had developed closer working relationships with new patrons, philanthropic foundations and the federal government.

    In late 1960s and early 1970s, student and faculty activists protested against the Vietnam War and The Massachusetts Institute of Technology ‘s defense research. In this period Massachusetts Institute of Technology’s various departments were researching helicopters, smart bombs and counterinsurgency techniques for the war in Vietnam as well as guidance systems for nuclear missiles. The Union of Concerned Scientists was founded on March 4, 1969 during a meeting of faculty members and students seeking to shift the emphasis on military research toward environmental and social problems. The Massachusetts Institute of Technology ultimately divested itself from the Instrumentation Laboratory and moved all classified research off-campus to the MIT Lincoln Laboratory facility in 1973 in response to the protests. The student body, faculty, and administration remained comparatively unpolarized during what was a tumultuous time for many other universities. Johnson was seen to be highly successful in leading his institution to “greater strength and unity” after these times of turmoil. However, six Massachusetts Institute of Technology students were sentenced to prison terms at this time and some former student leaders, such as Michael Albert and George Katsiaficas, are still indignant about MIT’s role in military research and its suppression of these protests. (Richard Leacock’s film, November Actions, records some of these tumultuous events.)

    In the 1980s, there was more controversy at The Massachusetts Institute of Technology over its involvement in SDI (space weaponry) and CBW (chemical and biological warfare) research. More recently, The Massachusetts Institute of Technology’s research for the military has included work on robots, drones and ‘battle suits’.

    Recent history

    The Massachusetts Institute of Technology has kept pace with and helped to advance the digital age. In addition to developing the predecessors to modern computing and networking technologies, students, staff, and faculty members at Project MAC, the Artificial Intelligence Laboratory, and the Tech Model Railroad Club wrote some of the earliest interactive computer video games like Spacewar! and created much of modern hacker slang and culture. Several major computer-related organizations have originated at MIT since the 1980s: Richard Stallman’s GNU Project and the subsequent Free Software Foundation were founded in the mid-1980s at the AI Lab; the MIT Media Lab was founded in 1985 by Nicholas Negroponte and Jerome Wiesner to promote research into novel uses of computer technology; the World Wide Web Consortium standards organization was founded at the Laboratory for Computer Science in 1994 by Tim Berners-Lee; the MIT OpenCourseWare project has made course materials for over 2,000 Massachusetts Institute of Technology classes available online free of charge since 2002; and the One Laptop per Child initiative to expand computer education and connectivity to children worldwide was launched in 2005.

    The Massachusetts Institute of Technology was named a sea-grant college in 1976 to support its programs in oceanography and marine sciences and was named a space-grant college in 1989 to support its aeronautics and astronautics programs. Despite diminishing government financial support over the past quarter century, MIT launched several successful development campaigns to significantly expand the campus: new dormitories and athletics buildings on west campus; the Tang Center for Management Education; several buildings in the northeast corner of campus supporting research into biology, brain and cognitive sciences, genomics, biotechnology, and cancer research; and a number of new “backlot” buildings on Vassar Street including the Stata Center. Construction on campus in the 2000s included expansions of the Media Lab, the Sloan School’s eastern campus, and graduate residences in the northwest. In 2006, President Hockfield launched the MIT Energy Research Council to investigate the interdisciplinary challenges posed by increasing global energy consumption.

    In 2001, inspired by the open source and open access movements, The Massachusetts Institute of Technology launched “OpenCourseWare” to make the lecture notes, problem sets, syllabi, exams, and lectures from the great majority of its courses available online for no charge, though without any formal accreditation for coursework completed. While the cost of supporting and hosting the project is high, OCW expanded in 2005 to include other universities as a part of the OpenCourseWare Consortium, which currently includes more than 250 academic institutions with content available in at least six languages. In 2011, The Massachusetts Institute of Technology announced it would offer formal certification (but not credits or degrees) to online participants completing coursework in its “MITx” program, for a modest fee. The “edX” online platform supporting MITx was initially developed in partnership with Harvard and its analogous “Harvardx” initiative. The courseware platform is open source, and other universities have already joined and added their own course content. In March 2009 the Massachusetts Institute of Technology faculty adopted an open-access policy to make its scholarship publicly accessible online.

    The Massachusetts Institute of Technology has its own police force. Three days after the Boston Marathon bombing of April 2013, MIT Police patrol officer Sean Collier was fatally shot by the suspects Dzhokhar and Tamerlan Tsarnaev, setting off a violent manhunt that shut down the campus and much of the Boston metropolitan area for a day. One week later, Collier’s memorial service was attended by more than 10,000 people, in a ceremony hosted by the Massachusetts Institute of Technology community with thousands of police officers from the New England region and Canada. On November 25, 2013, The Massachusetts Institute of Technology announced the creation of the Collier Medal, to be awarded annually to “an individual or group that embodies the character and qualities that Officer Collier exhibited as a member of The Massachusetts Institute of Technology community and in all aspects of his life”. The announcement further stated that “Future recipients of the award will include those whose contributions exceed the boundaries of their profession, those who have contributed to building bridges across the community, and those who consistently and selflessly perform acts of kindness”.

    In September 2017, the school announced the creation of an artificial intelligence research lab called the MIT-IBM Watson AI Lab. IBM will spend $240 million over the next decade, and the lab will be staffed by MIT and IBM scientists. In October 2018 MIT announced that it would open a new Schwarzman College of Computing dedicated to the study of artificial intelligence, named after lead donor and The Blackstone Group CEO Stephen Schwarzman. The focus of the new college is to study not just AI, but interdisciplinary AI education, and how AI can be used in fields as diverse as history and biology. The cost of buildings and new faculty for the new college is expected to be $1 billion upon completion.

    The Caltech/MIT Advanced aLIGO was designed and constructed by a team of scientists from California Institute of Technology , Massachusetts Institute of Technology, and industrial contractors, and funded by the National Science Foundation .

    Caltech /MIT Advanced aLigo

    It was designed to open the field of gravitational-wave astronomy through the detection of gravitational waves predicted by general relativity. Gravitational waves were detected for the first time by the LIGO detector in 2015. For contributions to the LIGO detector and the observation of gravitational waves, two Caltech physicists, Kip Thorne and Barry Barish, and Massachusetts Institute of Technology physicist Rainer Weiss won the Nobel Prize in physics in 2017. Weiss, who is also a Massachusetts Institute of Technology graduate, designed the laser interferometric technique, which served as the essential blueprint for the LIGO.

    The mission of The Massachusetts Institute of Technology is to advance knowledge and educate students in science, technology, and other areas of scholarship that will best serve the nation and the world in the twenty-first century. We seek to develop in each member of The Massachusetts Institute of Technology community the ability and passion to work wisely, creatively, and effectively for the betterment of humankind.

     
  • richardmitnick 3:36 pm on October 3, 2022 Permalink | Reply
    Tags: "SOAR Telescope Catches Dimorphos’s Expanding Comet-like Tail After DART Impact", , Astronomy, , , ,   

    From The National Science Foundation/ National Optical Astronomy Observatory NOIRLab (National Optical-Infrared Astronomy Research Laboratory) : “SOAR Telescope Catches Dimorphos’s Expanding Comet-like Tail After DART Impact” 

    From The National Science Foundation/ National Optical Astronomy Observatory NOIRLab (National Optical-Infrared Astronomy Research Laboratory)

    10.3.22
    Charles Blue
    Public Information Officer
    NSF’s NOIRLab
    Tel: +1 202 236 6324
    Email: charles.blue@noirlab.edu

    1
    The SOAR Telescope in Chile [below], operated by NSF’s NOIRLab, imaged the more than 10,000 kilometers long trail of debris blasted from the surface of Dimorphos two days after the asteroid was impacted by NASA’s DART spacecraft.

    NASA’s Double Asteroid Redirection Test (DART) spacecraft intentionally crashed into Dimorphos, the asteroid moonlet in the double-asteroid system of Didymos, on Monday 26 September 2022.

    This was the first planetary defense test in which an impact of a spacecraft attempted to modify the orbit of an asteroid.

    Two days after DART’s impact, astronomers Teddy Kareta (Lowell Observatory) and Matthew Knight (US Naval Academy) used the 4.1-meter Southern Astrophysical Research (SOAR) Telescope [1], at NSF’s NOIRLab’s Cerro Tololo Inter-American Observatory in Chile, to capture the vast plume of dust and debris blasted from the asteroid’s surface. In this new image, the dust trail — the ejecta that has been pushed away by the Sun’s radiation pressure, not unlike the tail of a comet — can be seen stretching from the center to the right-hand edge of the field of view, which at SOAR is about 3.1 arcminutes using the Goodman High Throughput Spectrograph. At Didymos’s distance from Earth at the time of the observation, that would equate to at least 10,000 kilometers (6000 miles) from the point of impact.

    “It is amazing how clearly we were able to capture the structure and extent of the aftermath in the days following the impact,” said Kareta.

    “Now begins the next phase of work for the DART team as they analyze their data and observations by our team and other observers around the world who shared in studying this exciting event,” said Knight. We plan to use SOAR to monitor the ejecta in the coming weeks and months. The combination of SOAR and AEON [2] is just what we need for efficient follow-up of evolving events like this one.”

    These observations will allow scientists to gain knowledge about the nature of the surface of Dimorphos, how much material was ejected by the collision, how fast it was ejected, and the distribution of particle sizes in the expanding dust cloud — for example, whether the impact caused the moonlet to throw off big chunks of material or mostly fine dust. Analyzing this information will help scientists protect Earth and its inhabitants by better understanding the amount and nature of the ejecta resulting from an impact, and how that might modify an asteroid’s orbit.

    SOAR’s observations demonstrate the capabilities of NSF-funded AURA facilities in planetary-defense planning and initiatives. In the future, Vera C. Rubin Observatory, funded by NSF and the US Department of Energy and currently under construction in Chile, will conduct a census of the Solar System to search for potentially hazardous objects.

    Didymos was discovered in 1996 with the UArizona 0.9-meter Spacewatch Telescope located at Kitt Peak National Observatory, a Program of NSF’s NOIRLab.
    Notes

    [1] SOAR is designed to produce the best quality images of any observatory in its class. Located on Cerro Pachón, SOAR is a joint project of the Ministério da Ciência, Tecnologia e Inovações do Brasil (MCTI/LNA), NSF’s NOIRLab, the University of North Carolina at Chapel Hill (UNC), and Michigan State University (MSU).

    [2] The Astronomical Event Observatory Network (AEON) is a facility ecosystem for accessible and efficient follow up of astronomical transients and Time Domain science. At the heart of the network, NOIRLab, with its SOAR 4.1-meter and Gemini 8-meter telescopes (and soon the Víctor M. Blanco 4-meter Telescope at CTIO), has joined forces with Las Cumbres Observatory to build such a network for the era of Vera C. Rubin Observatory’s Legacy Survey of Space and Time (LSST). SOAR is the pathfinder facility for incorporating the 4-meter-class and 8-meter-class telescopes into AEON.

    See the full article here.

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    What is NOIRLab?

    NSF’s NOIRLab (National Optical-Infrared Astronomy Research Laboratory), the US center for ground-based optical-infrared astronomy, operates the international Gemini Observatory (a facility of National Science Foundation, NRC–Canada, ANID–Chile, MCTIC–Brazil, MINCyT–Argentina, and Korea Astronomy and Space Science Institute [한국천문연구원] (KR)), NOAO Kitt Peak National Observatory (KPNO), Cerro Tololo Inter-American Observatory(CL) (CTIO), the Community Science and Data Center (CSDC), and Vera C. Rubin Observatory (in cooperation with DOE’s SLAC National Accelerator Laboratory). It is managed by the Association of Universities for Research in Astronomy (AURA) under a cooperative agreement with NSF and is headquartered in Tucson, Arizona. The astronomical community is honored to have the opportunity to conduct astronomical research on Iolkam Du’ag (Kitt Peak) in Arizona, on Mauna Kea in Hawaiʻi, and on Cerro Tololo and Cerro Pachón in Chile. We recognize and acknowledge the very significant cultural role and reverence that these sites have to the Tohono O’odham Nation, to the Native Hawaiian community, and to the local communities in Chile, respectively.

    National Science Foundation NOIRLab’s Gemini North Frederick C Gillett telescope at Mauna Kea Observatory in Hawai’i Altitude 4,213 m (13,822 ft).

    The National Science Foundation NOIRLab National Optical Astronomy Observatory Gemini South telescope on the summit of Cerro Pachón at an altitude of 7200 feet. There are currently two telescopes commissioned on Cerro Pachón, Gemini South and the SOAR Telescope — Southern Astrophysics Research Telescope. A third, the Vera C. Rubin Observatory, is under construction.

    The National Science Foundation NOIRLab National Optical Astronomy Observatory Vera C. Rubin Observatory [LSST] Telescope currently under construction on the El Peñón peak at Cerro Pachón Chile, a 2,682-meter-high mountain in Coquimbo Region, in northern Chile, alongside the existing NSF NOIRLab NOAO The Association of Universities for Research in Astronomy (AURA) Gemini South Telescope and Southern Astrophysical Research Telescope.

    Carnegie Institution for Science’s Las Campanas Observatory on Cerro Pachón in the southern Atacama Desert of Chile in the Atacama Region approximately 100 kilometres (62 mi) northeast of the city of La Serena, near the southern end and over 2,500 m (8,200 ft) high.

    National Science Foundation NOIRLab National Optical Astronomy Observatory Kitt Peak National Observatory on Kitt Peak of the Quinlan Mountains in the Arizona-Sonoran Desert on the Tohono O’odham Nation, 88 kilometers (55 mi) west-southwest of Tucson, Arizona, Altitude 2,096 m (6,877 ft), annotated.

    NSF NOIRLab NOAO Cerro Tololo Inter-American Observatory(CL) approximately 80 km to the East of La Serena, Chile, at an altitude of 2200 meters.

    The NOAO-Community Science and Data Center

    This work is supported in part by The Department of Energy Office of Science. The Dark Energy Survey is a collaboration of more than 400 scientists from 26 institutions in seven countries. Funding for the DES Projects has been provided by the US Department of Energy Office of Science, The National Science Foundation, Ministry of Science and Education of Spain, The Science and Technology Facilities Council (UK), The Higher Education Funding Council for England (UK), The Swiss Federal Institute of Technology ETH Zürich [Eidgenössische Technische Hochschule Zürich)](CH), The National Center for Supercomputing Applications at The University of Illinois at Urbana-Champaign, The Kavli Institute of Cosmological Physics at The University of Chicago, Center for Cosmology and AstroParticle Physics at The Ohio State University, Mitchell Institute for Fundamental Physics and Astronomy at The Texas A&M University, Brazil Funding Authority for Studies and Projects for Scientific and Technological Development [Financiadora de Estudos e Projetos ](BR) , Carlos Chagas Filho Foundation for Research Support of the State of Rio de Janeiro [Fundação Carlos Chagas Filho de Amparo à Pesquisa do Estado do Rio de Janeiro](BR), Ministry of Science, Technology, Innovation and Communications [Ministério da Ciência, Tecnolgia, Inovação e Comunicações](BR), German Research Foundation [Deutsche Forschungsgemeinschaft](DE), and the collaborating institutions in the Dark Energy Survey.

    The National Center for Supercomputing Applications at The University of Illinois at Urbana-Champaign provides
    supercomputing and advanced digital resources for the nation’s science enterprise. At NCSA, The University of Illinois faculty, staff, students, and collaborators from around the globe use advanced digital resources to address research grand challenges for the benefit of science and society. NCSA has been advancing one-third of the Fortune 50® for more than 30 years by bringing industry, researchers, and students together to solve grand challenges at rapid speed and scale.

    DOE’s Fermi National Accelerator Laboratory is America’s premier national laboratory for particle physics and accelerator research. A Department of Energy Office of Science laboratory, Fermilab is located near Chicago, Illinois, and operated under contract by the Fermi Research Alliance LLC, a joint partnership between The University of Chicago and The Universities Research Association, Inc.

    The DOE Office of Science is the single largest supporter of basic research in the physical sciences in the United States and is working to address some of the most pressing challenges of our time.

     
  • richardmitnick 12:56 pm on October 3, 2022 Permalink | Reply
    Tags: "Could Stripped Stars be False Positives in the Search for the Missing Black Holes?", , Astronomy, , , , , Theories suggest we should see ~10^7 stellar-mass black holes in the Milky Way.   

    From Astrobites : “Could Stripped Stars be False Positives in the Search for the Missing Black Holes?” 

    Astrobites bloc

    From Astrobites

    10.3.22
    Aldo Panfichi

    Title: Detecting Stripped Stars While Searching for Quiescent Black Holes

    Authors: Julia Bodensteiner et al.

    First Author’s Institution: The European Southern Observatory [La Observatorio Europeo Austral] [Observatoire européen austral][Europaiche Sûdsternwarte] (EU)(CL)

    Status: Published on ESO’s The Messenger [open access]

    Unraveling the mysteries behind the fates of the most massive stars is key to understanding the present state of the universe. This is because massive stars are origins of elements heavier than helium, as a result of thermonuclear interactions in their cores; as well as being sources of electromagnetic radiation, strong stellar winds, and supernovae, which help seed these elements throughout the cosmos. Since the most massive stars end their lives as black holes, understanding the distribution and characteristics of these objects is key to understanding the lifecycle of said stars.

    The problem with searching for black holes, however, is that by their very nature, they are nearly impossible to detect on their own. We infer their existence through two main techniques. The first is when a black hole accretes material from a stellar binary companion – this gas and dust can form an accretion disk around the black hole, heating up and emitting x-ray radiation. The second is from the detection of gravitational waves that occur when a black hole merges with another compact object.

    In our galaxy, we have detected around 100 or so black holes from X-ray binaries. However, since we expect most massive stars to end their lives as black holes, theories suggest we should see ~10^7 stellar-mass black holes in the Milky Way. As such, it is suspected that the vast majority of black holes are what we call quiescent – that is, they do not accrete enough to show up on x-ray observations, and thus can only be detected via gravitational effects on other nearby bodies.

    Searching Spectroscopically

    To date there have been only a handful of reported candidate quiescent black holes. These have all been in binary systems, whose initial signature was detected through spectroscopy and radial velocity measurements. In short, if looking at the light spectrum of a star shows its spectral lines varying sinusoidally, as if orbiting a companion, but there are no appropriate lines that vary in opposite cadence, it could represent an unseen companion that does not emit light – such as a black hole.

    The authors of today’s paper, however, caution that a black hole need not be the only explanation for this. There could instead be a companion star that is emitting light, but is not detected due to low-quality data or being relatively faint compared to the much brighter companion. Alternatively, it could be rotating so fast that its spectral lines are broad and shallow, and thus are much less distinguishable, among other theories.

    In particular, the authors look in detail at two systems – LB-1 and HR 6819 – whose initial spectra prompted them to be reported as quiescent black holes orbited by a B-type star (luminous, blue, and usually more massive than the sun). However, subsequent analyses have proposed that they are instead binary star systems that consist of a B-type star whose atmosphere has been stripped, and another luminous star.

    The spectra of LB-1 and HR 6819 both share similar features that are shown in Figure 1. In particular, in this wavelength region there are two bright, stationary, broad emission lines, and two dark, narrow, shallow absorption lines, which vary sinusoidally in time. The absorption lines are those of the B-type star, and vary on a scale of tens of days. The emission lines are instead characteristic of a classical Be star – a specific kind of B-type star that contains an emitting circumstellar gaseous disk.

    1
    Figure 1: Spectra of HR 6189, cut around the Fe II spectral line region at 5316 Angstroms, over the full orbital period of 40 days. The top panel shows the two bright, stationary emission lines of a classical Be star, and two darker, sinusoidally-varying absorption lines from a typical B-type star. The bottom panel shows three normalized spectra taken at three different phases in the orbit. Figure 2 in the paper.

    The initial hypothesis was that since the Be emission lines appear stationary, the B-star and Be star did not orbit one another closely. Either the B-star must orbit with an invisible companion, and the Be emission corresponded to either an unrelated third star which appeared in the spectra due to chance superposition, or this was a triple star system and the Be-star orbited much further away. These ideas were backed up by calculations which showed that if the B-type star had its typical mass of ~5 solar masses, the Be star would need to have an unphysical mass to have such an effect on the radial velocity of the B-type star’s spectral lines.

    The Stripped Star Solution

    However, subsequent studies have since suggested that such a triple system would most likely be unstable. Furthermore, the Be star’s emission lines do in fact seem to show a very small, subtle variation in opposite cadence to the B-star’s absorption lines; thus the two stars could in fact be orbiting one another, removing the need for a third, invisible companion. If this is the case, then, how do we justify the non-physicality of the Be star’s estimated mass? The projected orbital velocity of the B-type stars, based on the movement of their spectral lines, is much larger than it should be in comparison to that of the Be stars, in both the LB-1 and HR 6819 systems.

    We can resolve this by reinterpreting the physical nature of the B-type star. If we assume its mass to be on the order of ~0.5 solar masses, rather than the typical ~5-6, the radial velocities would make sense. Under this interpretation, the B-type star is not a standard main-sequence B-type star, but is instead in a “post-mass-transfer” phase – a star that has been fully ‘stripped’ by its binary companion, losing the majority of its mass, while its companion accreted all that matter and angular momentum, spinning up into a rapidly rotating Be star. As the outer hydrogen layers were stripped away from the B-type star, its now exposed Helium core would puff outwards and re-contract into a new equilibrium phase. In the early contraction phase, its luminosity and surface temperature can appear to overlap with those of a typical main-sequence B-type star, and thus it could be easily confused for one. If this is the case, then said B-type star would continue contracting over millions of years, eventually becoming a sub-dwarf OB star. The start of the contraction phase, however, is the brightest and most easily spectroscopically detectable phase of this evolution, and so it makes sense that these systems are detected in this phase.

    2
    Figure 2: Two hypotheses for the observed spectra of HR 6819. The first scenario corresponds to a stripped B-type star and a Be star orbiting each other. The second scenario shows a normal B-type star orbiting a black hole, with a Be star forming a part of this triple system, orbiting from much further away. Figure 3 in the paper.

    The authors posit that high-resolution interferometry might be the definitive way to determine whether these systems contain quiescent black holes or stripped B-type stars. The binary scenario has the two companions orbiting at 1-2 milliarcsecond separations, with an orbital period on the order of tens of days. On the other hand, the triple scenario should have the Be star orbiting much further apart, and appearing stationary on month-long timescales. Initial observations of HR 6819 from the GRAVITY instrument at the VLT Interferometer seem to favor the binary hypothesis, and further observations in April-September of 2022 will allow for the derivation of stellar parameters such as an accurate mass of the stripped B-type star. Similarly, GRAVITY observations of LB-1 are planned for this year, and will hopefully shed light on the nature of that system as well.

    With the possible elimination of these two candidates, however, the search for the missing quiescent black holes continues, and the authors hope that the lessons learned from these two systems pushes for an interdisciplinary approach to finding and characterizing these objects, in particular with ongoing and upcoming large scale surveys on the horizon.

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.


    Stem Education Coalition

    What do we do?

    Astrobites is a daily astrophysical literature journal written by graduate students in astronomy. Our goal is to present one interesting paper per day in a brief format that is accessible to undergraduate students in the physical sciences who are interested in active research.
    Why read Astrobites?

    Reading a technical paper from an unfamiliar subfield is intimidating. It may not be obvious how the techniques used by the researchers really work or what role the new research plays in answering the bigger questions motivating that field, not to mention the obscure jargon! For most people, it takes years for scientific papers to become meaningful.

    Our goal is to solve this problem, one paper at a time. In 5 minutes a day reading Astrobites, you should not only learn about one interesting piece of current work, but also get a peek at the broader picture of research in a new area of astronomy.

     
  • richardmitnick 11:37 am on October 2, 2022 Permalink | Reply
    Tags: "Asteroids in the Archives", , Astronomy, , , ,   

    From Astrobites : “Asteroids in the Archives” 

    Astrobites bloc

    From Astrobites

    10.1.22
    Ben Cassese

    Title: Hubble Asteroid Hunter. I. Identifying asteroid trails in Hubble Space Telescope images

    Authors: Sandor Kurk + 13 others

    First Author’s Institution: European Space Research and Technology Centre (ESA), Keplerlaan 1, 2201 AZ Noordwijk, The Netherlands

    Status: Published in A&A [open access]

    ______________________________________________________________
    Strong Motivations for Small Targets

    Though none of them were around to see it, astronomers are pretty confident that the early days of the solar system’s life were chaotic and violent. Scores of newly formed asteroids, planetesimals, and a few bona fide giant planets were all buzzing around the sun in a tightly packed disk: Collisions were inevitable, though their aftermaths varied. Sometimes two clumsy objects would merge together, and sometimes one or both would shatter into smaller pieces.

    To get a handle on just how lawless this epoch of our history was, astronomers would love to perform a forensic analysis on the asteroids that survived to the comparatively quiescent present; if they could measure the current ratio of smaller asteroids to larger ones, they could constrain how common destructive collisions were in the past. This in turn would inform models of where objects were and how fast they moved in the early days around the sun.

    Unfortunately, the most valuable asteroids for such a study –the very smallest remains– are also the hardest to find. We can only see asteroids when they reflect some sunlight back towards the earth, and small rocks just don’t reflect much light, making them very faint.

    Enter the Hubble Space Telescope. Hubble is a very capable, very busy space-based telescope that is able to see these dim asteroid remnants.

    However, although Hubble is able to image solar system objects, it spends most of its time gazing much further afield, staring longingly at distant galaxies, quasars, and other targets at cosmic distances.

    But, sometimes would-be asteroid hunters get lucky, and even when Hubble is trying to measure something else, a local space rock serendipitously wanders into the field of view. Since both the asteroid and the earth are moving around the sun, the photobombing asteroid appears as a curved streak in the image, a hairline fracture in the otherwise dark background of the universe.

    1
    Figure 1: An example of an asteroid trail in a Hubble image and the AutoML model’s successful recovery of it. The large galaxy is HCG007. Source: Figure 4a in the paper.

    Today’s authors aimed to wring as much information as possible out of these happy coincidences, and ambitiously sought to search the entire archive of relevant Hubble images for fortuitous streaks caused by covert, small asteroids .

    Citizen Science + Deep Learning

    Every picture Hubble takes eventually becomes public, freely downloadable to anyone who wants to see some corner of the universe. The archive of these images is immense, containing more than 37,000 images taken with the instruments and filters the authors deemed most likely to catch their targets. The scale of the database necessitates automation, and to meet this need the authors turned to deep learning, specifically Google’s Cloud AutoML Vision model. When fed an image, this algorithm reports back what’s in the picture (in this case, an asteroid, while in others, a dog for example). While they don’t detail the specifics of the architecture in this article, they share that the model consists of several interwoven machine learning components: they use a convolutional neural network to actually find the asteroid arcs in the images, but that network was itself designed by a reinforcement learning algorithm, an artificial intelligence paradigm that trains a computer to find an optimal solution via trial and error and feedback from its own actions.

    Such a machine learning model needs to be trained, and training requires a catalog of known examples for the model to study. Since such a catalog didn’t yet exist, the authors had to build their own, and to do so they enlisted the help of citizen scientists. They set up a project on Zooniverse called Hubble Asteroid Hunter, and over about a year more than 11,000 volunteers logged on to comb through the data and search for asteroid arcs by eye. Each volunteer was shown several Hubble pictures, asked “Is there an asteroid in this image?” for each one, then prompted to dismiss images with no streaks and flag pictures that contained the telltale curves. These volunteers collectively submitted more than 2 million yes/no answers to the query, and in total this tremendous effort uncovered asteroid streaks in about 1% of all images.

    Model Performance

    Combining the trails found by volunteers and those found by the model, the authors assembled a pile of 2,487 possible asteroid arcs. They then went through each of these candidates manually, and after removing duplicates and accounting for false positives caused by cosmic rays, gravitational lenses, or earth-bound satellites, they culled the list down to 1,701 confident asteroid detections.

    2
    Figure 2: The distribution of apparent magnitude, or perceived brightness, of the asteroids found in Hubble images. In blue are objects that the authors could trace back to previously-recorded asteroids, while in orange are the authors’ new candidate discoveries. Note that their new asteroids are systematically fainter than previous discoveries due to the challenges of detecting fainter bodies from Earth’s surface. Source: Figure 9a in the paper.

    After checking if any of these streaks could be attributed to any of the more than 1.2 million known asteroids, the authors concluded that 670 of the streaks corresponded to previously discovered sources and that the remaining 1,031 were caused by never-before-seen asteroids. They also found that these freshly discovered asteroids were systematically fainter than the known bodies, which they expected: the brighter an asteroid is, the higher the chance that it was already detected by a ground-based survey. This general faintness also hinted that many of their new discoveries are exactly the type of small asteroid which we’ve struggled to count in other surveys.

    The authors also start to explore other properties of their sample of new asteroids, including their spatial distribution and brightness variability. Though they do not account for the biases of Hubble’s preferential pointing and leave much of this further analysis for future work, their presentation of this new sample and demonstration of the power of merging citizen science and machine learning is an exciting step forward in the small-asteroid accounting business. The more confidently we can count the small asteroids, the closer we can come to understanding our solar system’s early history: now, if more drift into our view, we’ll be ready for them.

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.


    Stem Education Coalition

    What do we do?

    Astrobites is a daily astrophysical literature journal written by graduate students in astronomy. Our goal is to present one interesting paper per day in a brief format that is accessible to undergraduate students in the physical sciences who are interested in active research.
    Why read Astrobites?

    Reading a technical paper from an unfamiliar subfield is intimidating. It may not be obvious how the techniques used by the researchers really work or what role the new research plays in answering the bigger questions motivating that field, not to mention the obscure jargon! For most people, it takes years for scientific papers to become meaningful.

    Our goal is to solve this problem, one paper at a time. In 5 minutes a day reading Astrobites, you should not only learn about one interesting piece of current work, but also get a peek at the broader picture of research in a new area of astronomy.

     
  • richardmitnick 10:52 am on October 2, 2022 Permalink | Reply
    Tags: "The 'Wow!' Signal:: New search comes up empty", , Astronomy, , , , ,   

    From “EarthSky” : “The ‘Wow!’ Signal:: New search comes up empty” 

    1

    From “EarthSky”

    10.2.22
    Paul Scott Anderson

    1
    The famous Wow! Signal, detected by the Big Ear Radio Observatory on August 15, 1977. It’s still a leading candidate for an intelligent extraterrestrial radio signal. But astronomers heard it just once, and never again. Image via Big Ear Radio Observatory/ North American Astrophysical Observatory/ Wikimedia Commons (Public Domain).

    The famous Wow! Signal is still one of the most intriguing candidate radio signals ever found in the search for extraterrestrial intelligence (SETI). To this day, scientists have not explained its origin. The Ohio State University’s Big Ear radio telescope picked up the signal near the 21-cm hydrogen line at 1420 MHz. It was tantalizing. But it lasted only 72 seconds and then was gone … and has never returned.

    Scientists searched, and watched, but never heard the signal again. Was it a case of radio interference from Earth? An unknown type of natural radio signal? Or could it, in fact, have been a genuine signal from an alien civilization? We may never know for sure. But astronomers are still trying to pinpoint its origin.

    Now, the Breakthrough Listen team is reporting the results of their own search for a repeat of the elusive Wow! Signal. They published their new peer-reviewed paper in the September 2022 issue of Research Notes of the AAS [below].

    Did the Wow! Signal come from a sun-like star?

    The new search focused on the sun-like star 2MASS 19281982-2640123, which lies in the direction of the first detected signal. Moreover, it is much like our own sun, with similar temperature, radius and luminosity. It is 1,788 light-years away from Earth in the constellation Sagittarius. Previously, astronomer Alberto Caballero had identified the star in 2020 as a possible source for the Wow! Signal.

    The original Big Ear radio telescope used two feed horns for listening, one positive and the other negative. Caballero’s team, using data from the Gaia mission, found 38 and 28 K- and G-type stars in the horns’ detectability range, respectively. Ultimately, the researchers identified 2MASS 19281982-2640123 as the only sun-like star that in that group.

    The Breakthrough Listen team, however, used more advanced filtering criteria for analyzing the stars in the region. They actually found eight sun-like stars in the region where the Wow! Signal originated.

    Breakthrough Listen used both the Green Bank Telescope (two 30-minute observations) and the Allen Telescope Array (six 5-minute observations).

    SETI Institute/Allen Telescope Array situated at the Hat Creek Radio Observatory, 290 miles (470 km) northeast of San Francisco, California, Altitude 986 m (3,235 ft), the origins of the Institute’s search.

    The search focused on the L-band portion of the radio spectrum (1-2 GHz). Specifically, the team looked for narrow band signals, which would be most likely to be artificial. Both telescopes scanned the sky for a period of nine minutes and 40 seconds.

    New search for the Wow! Signal: nothing found

    So, what was the result? Unfortunately, as with previous searches, the researchers didn’t find anything. As Breakthrough Listen stated:

    “No technosignature candidates were found, although there remains an abundance of other stars from which the signal could have originated.”

    As the paper noted:

    “Both telescope observations had an overlap of 580 s. While blind searches using radio telescopes have been conducted in the general field of view in which the Wow! Signal was first detected, this is the first time a targeted search has been done. No technosignature candidates were detected.”

    It’s another disappointing result, but as noted, there are at least eight sun-like stars in the region where the signal may have originated. Sooner or later, future observations could target some of these stars.

    What about other stars?

    In general, we think of sun-like stars as ideal targets, since life on Earth evolved with the same kind of star, our sun. But what about red dwarfs? Significantly, they are the most common type of star in our galaxy, and astronomers have found many exoplanets orbiting them, including rocky worlds like Earth. We don’t yet know what the chances are for life to originate on planets around red dwarfs, but from what we do know so far, it seems there’s a reasonable chance. How many of these stars are in the Wow! Signal listening zone?

    Science paper:
    Research Notes of the AAS

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings
    Please help promote STEM in your local schools.


    Stem Education Coalition

    Deborah Byrd created the EarthSky radio series in 1991 and founded EarthSky.org in 1994. Today, she serves as Editor-in-Chief of this website. She has won a galaxy of awards from the broadcasting and science communities, including having an asteroid named 3505 Byrd in her honor. A science communicator and educator since 1976, Byrd believes in science as a force for good in the world and a vital tool for the 21st century. “Being an EarthSky editor is like hosting a big global party for cool nature-lovers,” she says.

     
  • richardmitnick 9:44 am on October 1, 2022 Permalink | Reply
    Tags: "Penn State’s high-precision X-ray instrument makes its first trip to space", "tREXS": the Rockets for Extended-Source X-ray Spectroscopy, , Astronomy, , , , , The Eberly College of Science   

    From The Eberly College of Science At Pennsylvania State University: “Penn State’s high-precision X-ray instrument makes its first trip to space” 

    2

    From The Eberly College of Science

    At

    Penn State Bloc

    Pennsylvania State University

    9.30.22
    Randall McEntaffer
    rlm90@psu.edu

    Gail McCormick
    gailmccormick@psu.edu
    Work Phone: 814-863-0901

    1
    Randall McEntaffer, professor and head of astronomy and astrophysics at Penn State, makes adjustments to the flight electronics and power supply of the X-ray spectrometer that he and his team built for a September rocket launch with NASA. The spectrometer observed the X-ray spectrum from a supernova remnant while testing critical technologies. Credit: Patrick Mansell / Penn State.

    A new X-ray instrument — designed, fabricated, and prepared for flight by a team from Penn State — recently scanned an exploded star while testing technology for future NASA missions.

    The instrument, called the Rockets for Extended-Source X-ray Spectroscopy, or tREXS, took its first flight aboard a NASA sounding rocket. In a brief suborbital trip, which launched Sept. 25, 2002, from the White Sands Missile Range in New Mexico, tREXS focused on a supernova (the remains of a star) that erupted some 5,000 years ago, uncovering new details about the elements it left behind.

    “With this flight, we targeted the Cygnus Loop, a supernova remnant located about 1,000 light years away and a source of diffuse X-rays in the constellation Cygnus,” said Randall McEntaffer, professor and head of astronomy and astrophysics at Penn State and the principal investigator for tREXS. “We successfully recovered the payload the next day and were able to recover all data stored onboard. Now we’ll start to dig through it to extract the X-ray photons that are the scientific purpose of this mission.”

    X-rays are typically too energetic to be seen by humans but are commonly produced in space. They flash during solar flares and radiate from distant supernovae. In fact, the entire night sky glows with X-rays emitted by the hot gases surrounding our solar system and neighboring stars. Like visible light, X-rays come in a range of wavelengths, or colors, and each wavelength tells its own story. tREXS is an X-ray spectrometer, designed to split X-ray light into its spectrum, or component wavelengths, to uncover information about where the X-rays came from.

    tREXS has two special features that set it apart from other spectrometers, the first being its remarkable precision. When light enters a spectrometer, it bounces off a diffraction grating, which splits the light apart because different wavelengths bounce off at slightly different angles, spreading out into a spectrum. Because of the way the gratings on tREXS were designed and built, they can separate wavelengths with extreme precision.

    “We built the gratings on tREXS molecule-by-molecule in the nanofabrication lab at Penn State,” said McEntaffer. “The gratings are our pride and joy.”

    2
    The team puts the final touches on tREXS before it left Penn State. Credit: Patrick Mansell/Penn State.

    3
    Research technician Jessica Mondoskin inspecting the vacuum pump attached to the soft x-ray spectrometer prior to its leaving Penn State. Credit: Patrick Mansell/Penn State.

    4
    Members of the McEntaffer group work to retrieve the data-carrying components stored on board the rocket. Credit: Ryan Harty/ Penn State.

    Second, tREXS uses a new technique, which McEntaffer calls their “light bucket.” Most spectrometers capture light through a narrow slit, which allows a “bar” of light to shine onto the diffraction grating. A narrow slit gives the instrument higher resolution, but it limits the light that can get through. This can pose a problem when studying faint sources of X-rays that are not a single point on the sky but are extended, or diffuse, like the sources McEntaffer studies.

    The trick tREXS employs is to use 250 distinct slits. Each slit captures light from adjacent parts of the sky, which are then focused to the same narrow bar of light. This combined light — which McEntaffer refers to as their “light bucket” — keeps many advantages of a narrow-slit design while providing much more light to work with.

    “Your sensitivity depends on how much light you collect,” McEntaffer said. “So we collect more light by making a larger light bucket and covering much more area on the sky.”

    For the recent flight, tREXS launched on a sounding rocket, which makes brief trips to space before falling back to Earth some 20 to 30 minutes later. Once above the atmosphere, tREXS had about 4 minutes and 40 seconds to observe the Cygnus Loop before descending back to Earth for recovery.

    After this successful flight, the team now hopes to adapt the instrument to study the diffuse X-ray background. This ambient X-ray light illuminates the entire night sky and emanates from the Local Bubble, the low-density region of our galaxy home to our Sun and nearest stellar neighbors.

    “We’re living in a bubble of hot gas and we really don’t understand its characteristics,” McEntaffer said. “That’s the ultimate goal — but we’re doing interesting science on the way to it.”

    Members of McEntaffer’s group at Penn State who significantly contributed to the project include James Tutt, Drew Miles, and Ross McCurdy. NASA’s Sounding Rocket Program is conducted at the agency’s Wallops Flight Facility at Wallops Island, Virginia, which is managed by NASA’s Goddard Space Flight Center in Greenbelt, Maryland. NASA’s Heliophysics Division manages the sounding rocket program for the agency. The development of the tREXS payload was supported by NASA’s Astrophysics Division.

    See the full article here .

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    The Eberly College of Science is the science college of Penn State University, University Park, Pennsylvania. It was founded in 1859 by Jacob S. Whitman, professor of natural science. The College offers baccalaureate, master’s, and doctoral degree programs in the basic sciences. It was named after Robert E. Eberly.

    Academics Eberly College of Science offers sixteen majors in four disciplines: Life Sciences, Physical Sciences, Mathematical Sciences and Interdisciplinary Studies.
    • The Life Sciences: Biology, Biochemistry & Molecular Biology, Biotechnology, Microbiology
    • The Physical Sciences: Astronomy & Astrophysics, Chemistry, Physics, Planetary Science and Astronomy
    • The Mathematical Sciences: Mathematics, Statistics, Data Sciences
    • Interdisciplinary Programs: General Science, Forensic Science, Premedicine, Integrated Premedical-Medical, Science BS/MBA

    Penn State Campus

    The Pennsylvania State University is a public state-related land-grant research university with campuses and facilities throughout Pennsylvania. Founded in 1855 as the Farmers’ High School of Pennsylvania, Penn State became the state’s only land-grant university in 1863. Today, Penn State is a major research university which conducts teaching, research, and public service. Its instructional mission includes undergraduate, graduate, professional and continuing education offered through resident instruction and online delivery. In addition to its land-grant designation, it also participates in the sea-grant, space-grant, and sun-grant research consortia; it is one of only four such universities (along with Cornell University, Oregon State University, and University of Hawaiʻi at Mānoa). Its University Park campus, which is the largest and serves as the administrative hub, lies within the Borough of State College and College Township. It has two law schools: Penn State Law, on the school’s University Park campus, and Dickinson Law, in Carlisle. The College of Medicine is in Hershey. Penn State is one university that is geographically distributed throughout Pennsylvania. There are 19 commonwealth campuses and 5 special mission campuses located across the state. The University Park campus has been labeled one of the “Public Ivies,” a publicly funded university considered as providing a quality of education comparable to those of the Ivy League.
    The Pennsylvania State University is a member of The Association of American Universities an organization of American research universities devoted to maintaining a strong system of academic research and education.
    Annual enrollment at the University Park campus totals more than 46,800 graduate and undergraduate students, making it one of the largest universities in the United States. It has the world’s largest dues-paying alumni association. The university offers more than 160 majors among all its campuses.

    Annually, the university hosts the Penn State IFC/Panhellenic Dance Marathon (THON), which is the world’s largest student-run philanthropy. This event is held at the Bryce Jordan Center on the University Park campus. The university’s athletics teams compete in Division I of the NCAA and are collectively known as the Penn State Nittany Lions, competing in the Big Ten Conference for most sports. Penn State students, alumni, faculty and coaches have received a total of 54 Olympic medals.

    Early years

    The school was sponsored by the Pennsylvania State Agricultural Society and founded as a degree-granting institution on February 22, 1855, by Pennsylvania’s state legislature as the Farmers’ High School of Pennsylvania. The use of “college” or “university” was avoided because of local prejudice against such institutions as being impractical in their courses of study. Centre County, Pennsylvania, became the home of the new school when James Irvin of Bellefonte, Pennsylvania, donated 200 acres (0.8 km2) of land – the first of 10,101 acres (41 km^2) the school would eventually acquire. In 1862, the school’s name was changed to the Agricultural College of Pennsylvania, and with the passage of the Morrill Land-Grant Acts, Pennsylvania selected the school in 1863 to be the state’s sole land-grant college. The school’s name changed to the Pennsylvania State College in 1874; enrollment fell to 64 undergraduates the following year as the school tried to balance purely agricultural studies with a more classic education.

    George W. Atherton became president of the school in 1882, and broadened the curriculum. Shortly after he introduced engineering studies, Penn State became one of the ten largest engineering schools in the nation. Atherton also expanded the liberal arts and agriculture programs, for which the school began receiving regular appropriations from the state in 1887. A major road in State College has been named in Atherton’s honor. Additionally, Penn State’s Atherton Hall, a well-furnished and centrally located residence hall, is named not after George Atherton himself, but after his wife, Frances Washburn Atherton. His grave is in front of Schwab Auditorium near Old Main, marked by an engraved marble block in front of his statue.

    Early 20th century

    In the years that followed, Penn State grew significantly, becoming the state’s largest grantor of baccalaureate degrees and reaching an enrollment of 5,000 in 1936. Around that time, a system of commonwealth campuses was started by President Ralph Dorn Hetzel to provide an alternative for Depression-era students who were economically unable to leave home to attend college.

    In 1953, President Milton S. Eisenhower, brother of then-U.S. President Dwight D. Eisenhower, sought and won permission to elevate the school to university status as The Pennsylvania State University. Under his successor Eric A. Walker (1956–1970), the university acquired hundreds of acres of surrounding land, and enrollment nearly tripled. In addition, in 1967, the Penn State Milton S. Hershey Medical Center, a college of medicine and hospital, was established in Hershey with a $50 million gift from the Hershey Trust Company.

    Modern era

    In the 1970s, the university became a state-related institution. As such, it now belongs to the Commonwealth System of Higher Education. In 1975, the lyrics in Penn State’s alma mater song were revised to be gender-neutral in honor of International Women’s Year; the revised lyrics were taken from the posthumously-published autobiography of the writer of the original lyrics, Fred Lewis Pattee, and Professor Patricia Farrell acted as a spokesperson for those who wanted the change.

    In 1989, the Pennsylvania College of Technology in Williamsport joined ranks with the university, and in 2000, so did the Dickinson School of Law. The university is now the largest in Pennsylvania. To offset the lack of funding due to the limited growth in state appropriations to Penn State, the university has concentrated its efforts on philanthropy.

    Research

    Penn State is classified among “R1: Doctoral Universities – Very high research activity”. Over 10,000 students are enrolled in the university’s graduate school (including the law and medical schools), and over 70,000 degrees have been awarded since the school was founded in 1922.

    Penn State’s research and development expenditure has been on the rise in recent years. For fiscal year 2013, according to institutional rankings of total research expenditures for science and engineering released by the National Science Foundation , Penn State stood second in the nation, behind only Johns Hopkins University and tied with the Massachusetts Institute of Technology , in the number of fields in which it is ranked in the top ten. Overall, Penn State ranked 17th nationally in total research expenditures across the board. In 12 individual fields, however, the university achieved rankings in the top ten nationally. The fields and sub-fields in which Penn State ranked in the top ten are materials (1st), psychology (2nd), mechanical engineering (3rd), sociology (3rd), electrical engineering (4th), total engineering (5th), aerospace engineering (8th), computer science (8th), agricultural sciences (8th), civil engineering (9th), atmospheric sciences (9th), and earth sciences (9th). Moreover, in eleven of these fields, the university has repeated top-ten status every year since at least 2008. For fiscal year 2011, the National Science Foundation reported that Penn State had spent $794.846 million on R&D and ranked 15th among U.S. universities and colleges in R&D spending.

    For the 2008–2009 fiscal year, Penn State was ranked ninth among U.S. universities by the National Science Foundation , with $753 million in research and development spending for science and engineering. During the 2015–2016 fiscal year, Penn State received $836 million in research expenditures.

    The Applied Research Lab (ARL), located near the University Park campus, has been a research partner with the Department of Defense since 1945 and conducts research primarily in support of the United States Navy. It is the largest component of Penn State’s research efforts statewide, with over 1,000 researchers and other staff members.

    The Materials Research Institute was created to coordinate the highly diverse and growing materials activities across Penn State’s University Park campus. With more than 200 faculty in 15 departments, 4 colleges, and 2 Department of Defense research laboratories, MRI was designed to break down the academic walls that traditionally divide disciplines and enable faculty to collaborate across departmental and even college boundaries. MRI has become a model for this interdisciplinary approach to research, both within and outside the university. Dr. Richard E. Tressler was an international leader in the development of high-temperature materials. He pioneered high-temperature fiber testing and use, advanced instrumentation and test methodologies for thermostructural materials, and design and performance verification of ceramics and composites in high-temperature aerospace, industrial, and energy applications. He was founding director of the Center for Advanced Materials (CAM), which supported many faculty and students from the College of Earth and Mineral Science, the Eberly College of Science, the College of Engineering, the Materials Research Laboratory and the Applied Research Laboratories at Penn State on high-temperature materials. His vision for Interdisciplinary research played a key role in creating the Materials Research Institute, and the establishment of Penn State as an acknowledged leader among major universities in materials education and research.

    The university was one of the founding members of the Worldwide Universities Network (WUN), a partnership that includes 17 research-led universities in the United States, Asia, and Europe. The network provides funding, facilitates collaboration between universities, and coordinates exchanges of faculty members and graduate students among institutions. Former Penn State president Graham Spanier is a former vice-chair of the WUN.

    The Pennsylvania State University Libraries were ranked 14th among research libraries in North America in the 2003–2004 survey released by The Chronicle of Higher Education. The university’s library system began with a 1,500-book library in Old Main. In 2009, its holdings had grown to 5.2 million volumes, in addition to 500,000 maps, five million microforms, and 180,000 films and videos.

    The university’s College of Information Sciences and Technology is the home of CiteSeerX, an open-access repository and search engine for scholarly publications. The university is also the host to the Radiation Science & Engineering Center, which houses the oldest operating university research reactor. Additionally, University Park houses the Graduate Program in Acoustics, the only freestanding acoustics program in the United States. The university also houses the Center for Medieval Studies, a program that was founded to research and study the European Middle Ages, and the Center for the Study of Higher Education (CSHE), one of the first centers established to research postsecondary education.

     
  • richardmitnick 1:53 pm on September 30, 2022 Permalink | Reply
    Tags: "Research News", Astronomy, , , , , Exploring the Plasma Loading Mechanism of Radio Jets Launched from Black Holes,   

    From Tohoku University[東北大学](JP): “Research News” 

    From Tohoku University[東北大学](JP)

    9.30.22

    1
    Exploring the Plasma Loading Mechanism of Radio Jets Launched from Black Holes

    Figure 2.
    2
    Photon spectrum of a reconnection-driven flare from M87. Parameters are M = 6.3 × 109 M⊙, $\dot{m}=5\times {10}^{-5}$, fl = 1.5, and ξhl = 0.5. The blue-dashed, green-dotted, and red-solid lines are for the high-energy flaring state, the low-energy flaring state, and their sum, respectively. The data points are obtained from Table A8 in EHT MWL Science Working Group et al. (2021), which is in the quiescent state. Our model predicts flares of ∼10 times higher luminosity. The black- and gray-dotted lines are sensitivity curves for HiZ-GUNDAM (2 × 104 s: Yonetoku et al. 2020) and AMEGO (106 s: McEnery et al. 2019), respectively.

    Figure 3.
    3
    Photon spectrum of a reconnection-driven flare from Sgr A* (solid red line). Parameters are M = 4.0 × 106 M⊙, $\dot{m}=6\times {10}^{-7}$, fl =0.6, and ξhl = 0.5. The X-ray flare data (cyan and magenta regions) are taken from Nowak et al. (2012) and Barrière et al. (2014), respectively. The black-dashed line is the sensitivity curve for FORCE (100 s: Nakazawa et al. 2018).

    See the science paper for instructive images.

    Galaxies, including our Milky Way, host supermassive black holes in their centers, and their masses are millions to billions of times larger than the Sun. Some supermassive black holes launch fast-moving plasma outflows which emit strong radio signals, known as radio jets.

    Radio jets were first discovered in the 1970s. But much remains unknown about how they are produced, especially their energy source and plasma loading mechanism.

    Recently, the Event Horizon Telescope Collaboration uncovered radio images of a nearby black hole at the center of the giant elliptical galaxy M87. The observation supported the theory that the spin of the black hole powers radio jets but did little to clarify the plasma loading mechanism.

    Now, a research team, led by Tohoku University astrophysicists, has proposed a promising scenario that clarifies plasma loading mechanism into radio jets.

    Recent studies have claimed that black holes are highly magnetized because magnetized plasma inside galaxies carries magnetic fields into the black hole. Then, neighboring magnetic energy transiently releases its energy via magnetic reconnection, energizing the plasma surrounding the black hole. This magnetic reconnection provides the energy source for solar flares.

    Plasmas in solar flares give off ultraviolet and X-rays; whereas the magnetic reconnection around the black hole can cause gamma-ray emission since the released energy per plasma particle is much higher than that for a solar flare.

    The present scenario proposes that the emitted gamma rays interact with each other and produce copious electron-positron pairs, which are loaded into the radio jets.

    This explains the large amount of plasma observed in radio jets, consistent with the M87 observations. Additionally, the scenario makes note that radio signal strengths vary from black hole to black hole. For example, radio jets around Sgr A* – the supermassive black hole in our Milky Way – are too faint and undetectable by current radio facilities.

    Also, the scenario predicts short-term X-ray emission when plasma is loaded into radio jets. These X-ray signals are missed with current X-ray detectors, but they are observable by planned X-ray detectors.

    “Under this scenario, future X-ray astronomy will be able to unravel the plasma loading mechanism into radio jets, a long-standing mystery of black holes,” points out Shigeo Kimura, lead author of the study.

    Details of Kimura and his team’s research were published in The Astrophysical Journal Letters on September 29, 2022.

    See the full article here.

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    Tohoku University (東北大学](JP), located in Sendai, Miyagi in the Tōhoku Region, Japan, is a Japanese national university. It was the third Imperial University in Japan, the first three Designated National University along with the The University of Tokyo[(東京大] (JP) and Kyoto University [京都大学](JP) and selected as a Top Type university of Top Global University Project by the Japanese government. In 2020 and 2021, the Times Higher Education Tohoku University was ranked No. 1 university in Japan.

    In 2016, Tohoku University had 10 faculties, 16 graduate schools and 6 research institutes, with a total enrollment of 17,885 students. The university’s three core values are “Research First [研究第一主義],” “Open-Doors [門戸開放],” and “Practice-Oriented Research and Education [実学尊重].”

    Faculties

    Arts and Letters
    Education
    Law
    Economics
    Science
    Medicine
    Dentistry
    Pharmaceutical Sciences
    Engineering
    Mechanical and Aerospace Engineering
    Information and Intelligent Systems
    Applied Chemistry, Chemical Engineering and Bio molecular Engineering
    Materials Science and Engineering
    Civil Engineering and Architecture
    Agriculture

    Graduate Schools

    Arts and Letters
    Education
    Law
    Economics and Management
    Science
    Medicine
    Dentistry
    Pharmaceutical Sciences
    Engineering
    Agricultural Sciences
    International Cultural Studies
    Information Sciences
    Life Sciences
    Environmental Studies
    Educational Informatics Research Division / Education Division

    Professional graduate schools

    Law School
    School of Public Policy
    Accounting School

    Research institutes

    Research Institute of Electrical Communication [電気通信研究所]
    Institute of Development, Aging and Cancer [加齢医学研究所]
    Institute of Fluid Science [流体科学研究所]
    Institute for Materials Research,IMR [金属材料研究所]

    National Collaborative Research Institute

    Institute of Multidisciplinary Research for Advanced Materials [多元物質科学研究所]

    International Research Institute of Disaster Science [災害科学国際研究所]

     
  • richardmitnick 9:13 am on September 24, 2022 Permalink | Reply
    Tags: "Star Light Star Bright … But Exactly How Bright?", Astronomy, , , , , , , Type 1A supernovae   

    From The National Institute of Standards and Technology: “Star Light Star Bright … But Exactly How Bright?” 

    From The National Institute of Standards and Technology

    9.22.22

    Technical Contacts

    Susana Deustua
    susana.deustua@nist.gov
    (301) 975-3763

    John T. Woodward IV
    john.woodward@nist.gov
    (301) 975-5495

    1
    NIST researcher John Woodward with the four-inch telescope used to calibrate the luminosity of nearby stars.
    Credit: C. Suplee/NIST.

    2
    Astronomers use the brightness of a type of exploding star known as a Type 1A supernova (seen here as bright blue dot to the left of a remote spiral galaxy) to determine the age and expansion rate of the universe. New calibrations of the luminosity of nearby stars, observed by NIST researchers, could help astronomers refine their measurements.
    Credit: J. DePasquale (STScI), M. Kornmesser and M. Zamani (ESA/Hubble), A. Riess (STScI/JHU)NASA, ESA, and the SH0ES team, and the Digitized Sky Survey.

    3
    The four-inch telescope on Mt. Hopkins in Arizona. Credit: J. Woodward/NIST.

    4
    Side view of the telescope undergoing testing in the laboratory. Credit: C. Suplee/NIST.

    A picture may be worth a thousand words, but for astronomers, simply recording images of stars and galaxies isn’t enough. To measure the true size and absolute brightness (luminosity) of heavenly bodies, astronomers need to accurately gauge the distance to these objects. To do so, the researchers rely on “standard candles”– stars whose luminosities are so well known that they act like light bulbs of known wattage.

    One way to determine a star’s distance from Earth is to compare how bright the star appears in the sky to its luminosity.

    But even standard candles need to be calibrated. For more than a decade, scientists at the National Institute of Standards and Technology (NIST) have been working to improve the methods for calibrating standard stars. They observed two nearby bright stars, Vega and Sirius, in order to calibrate their luminosity over a range of visible-light wavelengths. The researchers are now completing their analysis and plan to release the calibration data to astronomers within the next 12 months.

    The calibration data could aid astronomers who use more distant standard candles–exploded stars known as type Ia supernovas–to determine the age and expansion rate of the universe. (Comparing the brightness of remote type Ia supernovas to nearby ones led to the Nobel-prize winning discovery that the expansion of the universe is not slowing down, as expected, but is actually speeding up.)

    ______________________________________________________________________________

    4 October 2011

    The Royal Swedish Academy of Sciences has decided to award the Nobel Prize in Physics for 2011

    with one half to

    Saul Perlmutter
    The Supernova Cosmology Project
    The DOE’s Lawrence Berkeley National Laboratory and The University of California-Berkeley,

    and the other half jointly to

    Brian P. SchmidtThe High-z Supernova Search Team, The Australian National University, Weston Creek, Australia.

    and

    Adam G. Riess

    The High-z Supernova Search Team,The Johns Hopkins University and The Space Telescope Science Institute, Baltimore, MD.

    Written in the stars

    “Some say the world will end in fire, some say in ice…” *

    What will be the final destiny of the Universe? Probably it will end in ice, if we are to believe this year’s Nobel Laureates in Physics. They have studied several dozen exploding stars, called supernovae, and discovered that the Universe is expanding at an ever-accelerating rate. The discovery came as a complete surprise even to the Laureates themselves.

    In 1998, cosmology was shaken at its foundations as two research teams presented their findings. Headed by Saul Perlmutter, one of the teams had set to work in 1988. Brian Schmidt headed another team, launched at the end of 1994, where Adam Riess was to play a crucial role.

    The research teams raced to map the Universe by locating the most distant supernovae. More sophisticated telescopes on the ground and in space, as well as more powerful computers and new digital imaging sensors (CCD, Nobel Prize in Physics in 2009), opened the possibility in the 1990s to add more pieces to the cosmological puzzle.

    The teams used a particular kind of supernova, called Type 1a supernova. It is an explosion of an old compact star that is as heavy as the Sun but as small as the Earth. A single such supernova can emit as much light as a whole galaxy. All in all, the two research teams found over 50 distant supernovae whose light was weaker than expected – this was a sign that the expansion of the Universe was accelerating. The potential pitfalls had been numerous, and the scientists found reassurance in the fact that both groups had reached the same astonishing conclusion.

    For almost a century, the Universe has been known to be expanding as a consequence of the Big Bang about 14 billion years ago. However, the discovery that this expansion is accelerating is astounding. If the expansion will continue to speed up the Universe will end in ice.

    The acceleration is thought to be driven by dark energy, but what that dark energy is remains an enigma – perhaps the greatest in physics today. What is known is that dark energy constitutes about three quarters of the Universe. Therefore the findings of the 2011 Nobel Laureates in Physics have helped to unveil a Universe that to a large extent is unknown to science. And everything is possible again.

    *Robert Frost, Fire and Ice, 1920
    ______________________________________________________________________________

    Astronomers may be able to use the NIST calibrations of Vega and Sirius to better compare the brightness of nearby and faraway type Ia supernovas, leading to more accurate measurements of the expansion of the universe and its age.

    In the ongoing NIST study, scientists observe the two nearby stars with a four-inch telescope they designed and placed atop Mount Hopkins in the desert of southern Arizona.

    John Woodward, Susana Deustua, and their colleagues have repeatedly observed the spectra, or colors, of light emitted by Vega (25 light-years away) and Sirius (8.6 light-years). One light-year, the distance that light travels through a vacuum is one year, is 9.46 trillion kilometers.

    At the beginning and end of each observing night, the researchers tilt the telescope downwards so that they can compare the stellar spectra to that of an artificial star–a quartz lamp whose luminosity has been exactly measured and placed 100 meters from the telescope.

    Before the scientists can directly make the comparisons, they must account for the effect of Earth’s atmosphere, which scatters and absorbs some of the starlight before it can reach the telescope. Although light from the ground-based lamp does not travel through the full depth of the atmosphere, some of it is scattered by air during its short, horizontal journey to the telescope.

    To assess how much of the ground-based light is scattered from the lamp, the NIST team measures the relative ratio of power generated by a helium-neon laser at its output and 100 m away, at the site of the lamp.

    To determine how much starlight is lost to the Earth’s atmosphere, the researchers record the amount of starlight reaching the telescope as it points in different directions, peering through different thicknesses of the atmosphere during the night. Changes in the amount of light recorded by the telescope as the night progresses allow astronomers to correct for the atmospheric absorption.

    Once Vega and Sirius are calibrated, astronomers can use those stars as steppingstones to calibrate the light from other stars. For instance, by using the same telescope, researchers can observe a set of slightly fainter stars—call them Set 2. The luminosity of those fainter stars can then be calibrated using Vega and Sirius as reference standards.

    Switching to a telescope large enough to observe both the newly calibrated Set 2, and a group of even fainter stars (call them Set 3), astronomers can calibrate the light from Set 3 in terms of Set 2. Astronomers can repeat the process as needed to calibrate light from extremely remote stars. In this way, astronomers will be able to transfer the NIST calibration of Vega and Sirius to stars that lie thousands to millions of light-years away.

    Next year, Deustua and Woodward will move their small telescope, now back at NIST, to the European Southern Observatory’s (ESO’s) Paranal Observatory in the high-altitude desert of northern Chile.

    With drier climate than Mt. Hopkins, the Chilean site promises more clear nights to observe Sirius and Vega and less moisture to absorb or scatter the light. The telescope will reside on a mountaintop away from ESO’s Very Large Telescope, a suite of four 8.2-m telescopes and four 1.2-m telescopes, so that the light from NIST’s quartz lamp won’t interfere with observations of distant galaxies.

    The team also plans to expand its repertoire of bright nearby stars to include Arcturus (37 light-years), Gamma Crucis (89 light-years), and Gamma Trianguli Australis (184 light-years) and to observe stars at longer, infrared wavelengths. The recently launched James Webb Space Telescope and the Roman Space Telescope, set for launch by the end of the decade, are designed to examine the universe at these wavelengths.

    The NIST researchers recently received seed money to build a larger telescope which could observe and calibrate fainter, more distant stars. That would allow astronomers to transfer the NIST calibration to remote standard candles more directly. Reducing the number of steppingstones between the stars observed by NIST and the stars astronomers are studying reduces calibration errors.

    See the full article here.

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    NIST Campus, Gaitherberg, MD.

    The National Institute of Standards and Technology‘s Mission, Vision, Core Competencies, and Core Values

    Mission

    To promote U.S. innovation and industrial competitiveness by advancing measurement science, standards, and technology in ways that enhance economic security and improve our quality of life.

    NIST’s vision

    NIST will be the world’s leader in creating critical measurement solutions and promoting equitable standards. Our efforts stimulate innovation, foster industrial competitiveness, and improve the quality of life.

    NIST’s core competencies

    Measurement science
    Rigorous traceability
    Development and use of standards

    NIST’s core values

    NIST is an organization with strong values, reflected both in our history and our current work. NIST leadership and staff will uphold these values to ensure a high performing environment that is safe and respectful of all.

    Perseverance: We take the long view, planning the future with scientific knowledge and imagination to ensure continued impact and relevance for our stakeholders.
    Integrity: We are ethical, honest, independent, and provide an objective perspective.
    Inclusivity: We work collaboratively to harness the diversity of people and ideas, both inside and outside of NIST, to attain the best solutions to multidisciplinary challenges.
    Excellence: We apply rigor and critical thinking to achieve world-class results and continuous improvement in everything we do.

    Background

    The Articles of Confederation, ratified by the colonies in 1781, contained the clause, “The United States in Congress assembled shall also have the sole and exclusive right and power of regulating the alloy and value of coin struck by their own authority, or by that of the respective states—fixing the standards of weights and measures throughout the United States”. Article 1, section 8, of the Constitution of the United States (1789), transferred this power to Congress; “The Congress shall have power…To coin money, regulate the value thereof, and of foreign coin, and fix the standard of weights and measures”.

    In January 1790, President George Washington, in his first annual message to Congress stated that, “Uniformity in the currency, weights, and measures of the United States is an object of great importance, and will, I am persuaded, be duly attended to”, and ordered Secretary of State Thomas Jefferson to prepare a plan for Establishing Uniformity in the Coinage, Weights, and Measures of the United States, afterwards referred to as the Jefferson report. On October 25, 1791, Washington appealed a third time to Congress, “A uniformity of the weights and measures of the country is among the important objects submitted to you by the Constitution and if it can be derived from a standard at once invariable and universal, must be no less honorable to the public council than conducive to the public convenience”, but it was not until 1838, that a uniform set of standards was worked out. In 1821, John Quincy Adams had declared “Weights and measures may be ranked among the necessities of life to every individual of human society”.

    From 1830 until 1901, the role of overseeing weights and measures was carried out by the Office of Standard Weights and Measures, which was part of the U.S. Coast and Geodetic Survey in the Department of the Treasury.

    Bureau of Standards

    In 1901 in response to a bill proposed by Congressman James H. Southard (R- Ohio) the National Bureau of Standards was founded with the mandate to provide standard weights and measures and to serve as the national physical laboratory for the United States. (Southard had previously sponsored a bill for metric conversion of the United States.)

    President Theodore Roosevelt appointed Samuel W. Stratton as the first director. The budget for the first year of operation was $40,000. The Bureau took custody of the copies of the kilogram and meter bars that were the standards for US measures, and set up a program to provide metrology services for United States scientific and commercial users. A laboratory site was constructed in Washington DC (US) and instruments were acquired from the national physical laboratories of Europe. In addition to weights and measures the Bureau developed instruments for electrical units and for measurement of light. In 1905 a meeting was called that would be the first National Conference on Weights and Measures.

    Initially conceived as purely a metrology agency the Bureau of Standards was directed by Herbert Hoover to set up divisions to develop commercial standards for materials and products. Some of these standards were for products intended for government use; but product standards also affected private-sector consumption. Quality standards were developed for products including some types of clothing; automobile brake systems and headlamps; antifreeze; and electrical safety. During World War I, the Bureau worked on multiple problems related to war production even operating its own facility to produce optical glass when European supplies were cut off. Between the wars Harry Diamond of the Bureau developed a blind approach radio aircraft landing system. During World War II military research and development was carried out including development of radio propagation forecast methods; the proximity fuze and the standardized airframe used originally for Project Pigeon; and shortly afterwards the autonomously radar-guided Bat anti-ship guided bomb and the Kingfisher family of torpedo-carrying missiles.

    In 1948, financed by the United States Air Force the Bureau began design and construction of SEAC: the Standards Eastern Automatic Computer. The computer went into operation in May 1950 using a combination of vacuum tubes and solid-state diode logic. About the same time the Standards Western Automatic Computer, was built at the Los Angeles office of the NBS by Harry Huskey and used for research there. A mobile version- DYSEAC- was built for the Signal Corps in 1954.

    Due to a changing mission, the “National Bureau of Standards” became the “ The National Institute of Standards and Technology” in 1988.

    Following September 11, 2001, NIST conducted the official investigation into the collapse of the World Trade Center buildings.

    Organization

    NIST is headquartered in Gaithersburg, Maryland, and operates a facility in Boulder, Colorado, which was dedicated by President Eisenhower in 1954. NIST’s activities are organized into laboratory programs and extramural programs. Effective October 1, 2010, NIST was realigned by reducing the number of NIST laboratory units from ten to six. NIST Laboratories include:

    Communications Technology Laboratory (CTL)
    Engineering Laboratory (EL)
    Information Technology Laboratory (ITL)
    Center for Neutron Research (NCNR)
    Material Measurement Laboratory (MML)
    Physical Measurement Laboratory (PML)

    Extramural programs include:

    Hollings Manufacturing Extension Partnership (MEP), a nationwide network of centers to assist small and mid-sized manufacturers to create and retain jobs, improve efficiencies, and minimize waste through process improvements and to increase market penetration with innovation and growth strategies;
    Technology Innovation Program (TIP), a grant program where NIST and industry partners cost share the early-stage development of innovative but high-risk technologies;
    Baldrige Performance Excellence Program, which administers the Malcolm Baldrige National Quality Award, the nation’s highest award for performance and business excellence.

    NIST’s Boulder laboratories are best known for NIST‑F1 which houses an atomic clock.

    NIST‑F1 serves as the source of the nation’s official time. From its measurement of the natural resonance frequency of cesium—which defines the second—NIST broadcasts time signals via longwave radio station WWVB near Fort Collins in Colorado, and shortwave radio stations WWV and WWVH, located near Fort Collins and Kekaha in Hawai’i, respectively.

    NIST also operates a neutron science user facility: the NIST Center for Neutron Research (NCNR).

    The NCNR provides scientists access to a variety of neutron scattering instruments which they use in many research fields (materials science; fuel cells; biotechnology etc.).

    The SURF III Synchrotron Ultraviolet Radiation Facility is a source of synchrotron radiation in continuous operation since 1961.

    SURF III now serves as the US national standard for source-based radiometry throughout the generalized optical spectrum. All NASA-borne extreme-ultraviolet observation instruments have been calibrated at SURF since the 1970s, and SURF is used for measurement and characterization of systems for extreme ultraviolet lithography.

    The Center for Nanoscale Science and Technology performs research in nanotechnology, both through internal research efforts and by running a user-accessible cleanroom nanomanufacturing facility.

    This “NanoFab” is equipped with tools for lithographic patterning and imaging (e.g., electron microscopes and atomic force microscopes).
    Committees

    NIST has seven standing committees:

    Technical Guidelines Development Committee (TGDC)
    Advisory Committee on Earthquake Hazards Reduction (ACEHR)
    National Construction Safety Team Advisory Committee (NCST Advisory Committee)
    Information Security and Privacy Advisory Board (ISPAB)
    Visiting Committee on Advanced Technology (VCAT)
    Board of Overseers for the Malcolm Baldrige National Quality Award (MBNQA Board of Overseers)
    Manufacturing Extension Partnership National Advisory Board (MEPNAB)

    Measurements and standards

    As part of its mission, NIST supplies industry, academia, government, and other users with over 1,300 Standard Reference Materials (SRMs). These artifacts are certified as having specific characteristics or component content, used as calibration standards for measuring equipment and procedures, quality control benchmarks for industrial processes, and experimental control samples.

    Handbook 44

    NIST publishes the Handbook 44 each year after the annual meeting of the National Conference on Weights and Measures (NCWM). Each edition is developed through cooperation of the Committee on Specifications and Tolerances of the NCWM and the Weights and Measures Division (WMD) of the NIST. The purpose of the book is a partial fulfillment of the statutory responsibility for “cooperation with the states in securing uniformity of weights and measures laws and methods of inspection”.

    NIST has been publishing various forms of what is now the Handbook 44 since 1918 and began publication under the current name in 1949. The 2010 edition conforms to the concept of the primary use of the SI (metric) measurements recommended by the Omnibus Foreign Trade and Competitiveness Act of 1988.

     
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