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  • richardmitnick 2:07 pm on July 12, 2018 Permalink | Reply
    Tags: Binary asteroid 2017 YE5, GBO -Green Bank Observatory, Goldstone Solar System Radar, ,   

    From JPL Caltech: “Observatories Team Up to Reveal Rare Double Asteroid” 

    NASA JPL Banner

    From JPL-Caltech

    July 12, 2018

    Calla Cofield
    Jet Propulsion Laboratory, Pasadena, Calif.
    818-393-1821
    Calla.e.cofield@jpl.nasa.gov

    JoAnna Wendel
    NASA Headquarters, Washington
    202-358-1003
    joanna.r.wendel@nasa.gov

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    Artist’s concept of what binary asteroid 2017 YE5 might look like. The two objects showed striking differences in radar reflectivity, which could indicate that they have different surface properties.Credit: NASA/JPL-Caltech

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    Observatories Team Up to Reveal Rare Double Asteroid
    Artist’s illustration of the trajectory of asteroid 2017 YE5 through the solar system. At its closest approach to Earth, the asteroid came to within 16 times the distance between Earth and the moon.Credit: NASA/JPL-Caltech

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    Observatories Team Up to Reveal Rare Double Asteroid
    This optical composite image shows asteroid 2017 YE5, taken on June 30, 2018, by the Cadi Ayyad University Morocco Oukaimeden Sky Survey, one of the first surveys to identify 2017 YE5 in December 2017. Credit: Cadi Ayyad University Morocco Oukaimeden Sky Survey

    New observations by three of the world’s largest radio telescopes have revealed that an asteroid discovered last year is actually two objects, each about 3,000 feet (900 meters) in size, orbiting each other.


    Three of the world’s largest radio telescopes team up to show a rare double asteroid. 2017 YE5 is only the fourth binary near-Earth asteroid ever observed in which the two bodies are roughly the same size, and not touching. This video shows radar images of the pair gathered by Goldstone Solar System Radar, Arecibo Observatory and Green Bank Observatory.

    NASA DSCC Goldstone Antenna California in the Mojave Desert, USA

    NAIC Arecibo Observatory operated by University of Central Florida, Yang Enterprises and UMET, Altitude 497 m (1,631 ft)

    Green Bank Radio Telescope, West Virginia, USA

    Near-Earth asteroid 2017 YE5 was discovered with observations provided by the Morocco Oukaimeden Sky Survey on Dec. 21, 2017, but no details about the asteroid’s physical properties were known until the end of June. This is only the fourth “equal mass” binary near-Earth asteroid ever detected, consisting of two objects nearly identical in size, orbiting each other. The new observations provide the most detailed images ever obtained of this type of binary asteroid.

    On June 21, the asteroid 2017 YE5 made its closest approach to Earth for at least the next 170 years, coming to within 3.7 million miles (6 million kilometers) of Earth, or about 16 times the distance between Earth and the Moon. On June 21 and 22, observations by NASA’s Goldstone Solar System Radar (GSSR) in California showed the first signs that 2017 YE5 could be a binary system. The observations revealed two distinct lobes, but the asteroid’s orientation was such that scientists could not see if the two bodies were separate or joined. Eventually, the two objects rotated to expose a distinct gap between them.

    Scientists at the Arecibo Observatory in Puerto Rico had already planned to observe 2017 YE5, and they were alerted by their colleagues at Goldstone of the asteroid’s unique properties. On June 24, the scientists teamed up with researchers at the Green Bank Observatory (GBO) in West Virginia and used the two observatories together in a bi-static radar configuration (in which Arecibo transmits the radar signal and Green Bank receives the return signal). Together, they were able to confirm that 2017 YE5 consists of two separated objects. By June 26, both Goldstone and Arecibo had independently confirmed the asteroid’s binary nature.

    The new observations obtained between June 21 and 26 indicate that the two objects revolve around each other once every 20 to 24 hours. This was confirmed with visible-light observations of brightness variations by Brian Warner at the Center for Solar System Studies in Rancho Cucamonga, California.

    Radar imaging shows that the two objects are larger than their combined optical brightness originally suggested, indicating that the two rocks do not reflect as much sunlight as a typical rocky asteroid. 2017 YE5 is likely as dark as charcoal. The Goldstone images taken on June 21 also show a striking difference in the radar reflectivity of the two objects, a phenomenon not seen previously among more than 50 other binary asteroid systems studied by radar since 2000. (However, the majority of those binary asteroids consist of one large object and a much smaller satellite.) The reflectivity differences also appear in the Arecibo images and hint that the two objects may have different densities, compositions near their surfaces, or different surface roughnesses.

    Scientists estimate that among near-Earth asteroids larger than 650 feet (200 meters) in size, about 15 percent are binaries with one larger object and a much smaller satellite. Equal-mass binaries like 2017 YE5 are much rarer. Contact binaries, in which two similarly sized objects are in contact, are thought to make up another 15 percent of near-Earth asteroids larger than 650 feet (200 meters) in size.

    The discovery of the binary nature of 2017 YE5 provides scientists with an important opportunity to improve understanding of different types of binaries and to study the formation mechanisms between binaries and contact binaries, which may be related. Analysis of the combined radar and optical observations may allow scientists to estimate the densities of the 2017 YE5 objects, which will improve understanding of their composition and internal structure, and of how they formed.

    Study contributors

    The Goldstone observations were led by Marina Brozovi?, a radar scientist at NASA’s Jet Propulsion Laboratory in Pasadena, California.

    Anne Virkki, Flaviane Venditti and Sean Marshall of the Arecibo Observatory and the University of Central Florida led the observations using the Arecibo Observatory.

    Patrick Taylor of the Universities Space Research Association (USRA), scientist at the Lunar and Planetary Institute, led the bi-static radar observations with GBO, home of the Green Bank Telescope (GBT), the world’s largest fully steerable radio telescope.

    The Arecibo, Goldstone and USRA planetary radar projects are funded through NASA’s Near-Earth Object Observations Program within the Planetary Defense Coordination Office (PDCO), which manages the Agency’s Planetary Defense Program. The Arecibo Observatory is a facility of the National Science Foundation operated under cooperative agreement by the University of Central Florida, Yang Enterprises, and Universidad Metropolitana. GBO is a facility of the National Science Foundation, operated under a cooperative agreement by Associated Universities, Inc.

    In addition to the resources NASA puts into understanding asteroids, the PDCO also partners with other U.S. government agencies, university-based astronomers, and space science institutes across the country, often with grants, interagency transfers and other contracts from NASA. They also collaborate with international space agencies and institutions that are working to track and better understand these smaller objects of the Solar System. In addition, NASA values the work of numerous highly skilled amateur astronomers, whose accurate observational data helps improve asteroid orbits after discovery.

    More information about asteroids and near-Earth objects is at these sites:

    https://cneos.jpl.nasa.gov

    https://www.jpl.nasa.gov/asteroidwatch

    See the full article here .


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    Please help promote STEM in your local schools.

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    NASA JPL Campus

    Jet Propulsion Laboratory (JPL) is a federally funded research and development center and NASA field center located in the San Gabriel Valley area of Los Angeles County, California, United States. Although the facility has a Pasadena postal address, it is actually headquartered in the city of La Cañada Flintridge, on the northwest border of Pasadena. JPL is managed by the nearby California Institute of Technology (Caltech) for the National Aeronautics and Space Administration. The Laboratory’s primary function is the construction and operation of robotic planetary spacecraft, though it also conducts Earth-orbit and astronomy missions. It is also responsible for operating NASA’s Deep Space Network.

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  • richardmitnick 1:45 pm on June 11, 2018 Permalink | Reply
    Tags: AME-anomalous microwave emission, , , ATCA-Australia Telescope Compact Array, , , Diamond Dust Shimmering around Distant Stars, GBO -Green Bank Observatory, Mysterious cosmic microwave “glow” emanating from several protoplanetary disks in our galaxy,   

    From Green Bank Observatory: Diamond Dust Shimmering around Distant Stars: Nanoscale gemstones source of mysterious cosmic microwave light 

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    Green Bank Radio Telescope, West Virginia, USA
    Green Bank Radio Telescope, West Virginia, USA

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    From Green Bank Observatory

    Press Release

    11 June 2018
    Paul Vosteen
    Media Specialist; Education & Public Outreach
    Green Bank Observatory
    +1.304.456.2212
    pvosteen@nrao.edu

    Some of the tiniest diamonds in the universe – bits of crystalline carbon hundreds of thousands of times smaller than a grain of sand – have been detected swirling around three infant star systems in the Milky Way. These microscopic gemstones are neither rare nor precious; they are, however, exciting for astronomers who identified them as the source of a mysterious cosmic microwave “glow” emanating from several protoplanetary disks in our galaxy.

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    Artist impression of nanoscale diamonds surrounding a young star in the Milky Way. Recent GBT and ATCA observations have identified the telltale radio signal of diamond dust around 3 such stars, suggesting they are a source of the so-called anomalous microwave emission. Credit: S. Dagnello, NRAO/AUI/NSF

    For decades, astronomers have puzzled over the exact source of a peculiar type of faint microwave light emanating from a number of regions across the Milky Way. Known as anomalous microwave emission (AME), this light comes from energy released by rapidly spinning nanoparticles – bits of matter so small that they defy detection by ordinary microscopes. (The period on an average printed page is approximately 500,000 nanometers across.)

    “Though we know that some type of particle is responsible for this microwave light, its precise source has been a puzzle since it was first detected nearly 20 years ago,” said Jane Greaves, an astronomer at Cardiff University in Wales and lead author on a paper announcing this result in Nature Astronomy.

    Until now, the most likely culprit for this microwave emission was thought to be a class of organic molecules known as polycyclic aromatic hydrocarbons (PAHs) – carbon-based molecules found throughout interstellar space and recognized by the distinct, yet faint infrared (IR) light they emit. Nanodiamonds — particularly hydrogenated nanodiamonds, those bristling with hydrogen-bearing molecules on their surfaces — also naturally emit in the infrared portion of the spectrum, but at a different wavelength.

    A series of observations with the National Science Foundation’s Green Bank Telescope (GBT) in West Virginia and the Australia Telescope Compact Array (ATCA) has — for the first time — homed in on three clear sources of AME light, the protoplanetary disks surrounding the young stars known as V892 Tau, HD 97048, and MWC 297. The GBT observed V892 Tau and the ATCA observed the other two systems.

    CSIRO ATCA at the Paul Wild Observatory, about 25 km west of the town of Narrabri in rural NSW about 500 km north-west of Sydney, AU

    “This is the first clear detection of anomalous microwave emission coming from protoplanetary disks,” said David Frayer a coauthor on the paper and astronomer with the Green Bank Observatory.

    The astronomers also note that the infrared light coming from these systems matches the unique signature of nanodiamonds. Other protoplanetary disks throughout the Milky Way, however, have the clear infrared signature of PAHs yet show no signs of the AME light.

    This strongly suggests that PAHs are not the mysterious source of anomalous microwave radiation, as astronomers once thought. Rather, hydrogenated nanodiamonds, which form naturally within protoplanetary disks and are found in meteorites on Earth, are the most likely source of AME light in our galaxy.

    “In a Sherlock Holmes-like method of eliminating all other causes, we can confidently say the best candidate capable of producing this microwave glow is the presence of nanodiamonds around these newly formed stars,” said Greaves. Based on their observations, the astronomers estimate that up to 1-2 percent of the total carbon in these protoplanetary disks has gone into forming nanodiamonds.

    Evidence for nanodiamonds in protoplanetary disks has grown over the past several decades. This is, however, the first clear connection between nanodiamonds and AME in any setting.

    Statistical models also strongly support the premise that nanodiamonds are abundant around infant stars and are responsible for the anomalous microwave emission found there. “There is a one in 10,000 chance, or less, that this connection is due to chance,” said Frayer.

    For their research, the astronomers used the GBT and ATCA to survey 14 young stars across the Milky Way for hints of anomalous microwave emission. AME was clearly seen in 3 of the 14 stars, which are also the only 3 stars of the 14 that show the IR spectral signature of hydrogenated nanodiamonds. “In fact, these are so rare,” notes Greaves, “no other young stars have the confirmed infrared imprint.”

    This detection has interesting implications for the study of cosmology and the search for evidence that our universe began with a period of inflation. If immediately after the Big Bang, our universe grew at a pace that vastly outstripped the speed of light, a trace of that period of inflation should be seen in a peculiar polarization of the cosmic microwave background. Though this signature of polarization has yet to be conclusively detected, the work by Greaves and her colleagues offers some hope that it could be.

    “This is good news for those who study polarization of the cosmic microwave background, since the signal from spinning nanodiamonds would be weakly polarized at best,” said Brian Mason, an astronomer at the National Radio Astronomy Observatory and coauthor on the paper. “This means that astronomers can now make better models of the foreground microwave light from our galaxy, which must be removed to study the distant afterglow of the Big Bang.”

    Nanodiamonds likely form out of a superheated vapor of carbon atoms in highly energized star-forming regions. This is not unlike industrial methods of creating nanodiamonds on Earth.

    In astronomy, nanodiamonds are special in that their structure produces what is known as a “dipole moment” – an arrangement of atoms that allows them to emit electromagnetic radiation when they spin. Because these particles are so small – smaller than normal dust particles in a protoplanetary disk — they are able to spin exceptionally fast, emitting radiation in the microwave range rather than in the meter-wavelength range, where galactic and intergalactic radiation would probably drown it out.

    “This is a cool and unexpected resolution to the puzzle of anomalous microwave radiation,” concluded Greaves. “It’s even more interesting that it was obtained by looking at protoplanetary disks, shedding light on the chemical features of early solar systems, including our own.”

    “It is an exciting result,” concluded co-author Anna Scaife from Manchester University. “It’s not often you find yourself putting new words to famous tunes, but ‘AME in the Sky with Diamonds’ seems a thoughtful way of summarizing our research.”

    Future centimeter-wave instruments, like the planned Band 1 receivers on ALMA and the Next Generation Very Large Array, will be able to study this phenomenon in much greater detail. Now that there is a physical model and, for the first time, a clear spectral signature, astronomers expect our understanding will improve quickly.

    See the full article here .


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    Please help promote STEM in your local schools.

    Stem Education Coalition

    gbo-science-building

    Mission Statement

    Green Bank Observatory enables leading edge research at radio wavelengths by offering telescope, facility and advanced instrumentation access to the astronomy community as well as to other basic and applied research communities. With radio astronomy as its foundation, the Green Bank Observatory is a world leader in advancing research, innovation, and education.

    History

    60 years ago, the trailblazers of American radio astronomy declared this facility their home, establishing the first ever National Radio Astronomy Observatory within the United States and the first ever national laboratory dedicated to open access science. Today their legacy is alive and well.

     
  • richardmitnick 3:59 pm on April 30, 2018 Permalink | Reply
    Tags: , , , , GBO -Green Bank Observatory, , , Phased Array Feeds,   

    From National Radio Astronomy Observatory via newswise: “New Technology Offers to Broaden Vision for Radio Astronomy” 

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    National Radio Astronomy Observatory

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    @newswise

    newswise

    30-Apr-2018

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    Infographic demonstrating the layout of the newly designed Phased Array Feed receiver that was tested on the Green Bank Telescope. Credit: NRAO/AUI/NSF; S. Dangello.



    GBO radio telescope, Green Bank, West Virginia, USA

    To accelerate the pace of discovery and exploration of the cosmos, a multi-institution team of astronomers and engineers has developed a new and improved version of an unconventional radio-astronomy imaging system known as a Phased Array Feed (PAF). This remarkable instrument can survey vast swaths of the sky and generate multiple views of astronomical objects with unparalleled efficiency.

    Looking nothing like a camera or other traditional imaging technologies – like CCDs in optical telescopes or single receivers in radio telescopes – this new Phased Array Feed design resembles a forest of miniature tree-like antennas evenly arranged on a meter-wide metal plate. When mounted on a single-dish radio telescope, specialized computers and signal processors are able to combine the signals among the antennas to create a virtual multi-pixel camera.

    This type of instrument is particularly useful in a number of important areas of astronomical research, including the study of hydrogen gas raining in on our galaxy and in searches for enigmatic Fast Radio Bursts.

    Over the years, various other radio astronomy research facilities have developed phased array receiver designs. Most, however, have not achieved the efficiency necessary to compete with classical radio receiver designs, which process one signal from one spot on the sky at a time. The value of the new PAF is that it can form multiple views (or “beams on the sky,” in radio astronomy terms) with the same efficiency as a classical receiver, which can enable faster scans of multiple astronomical targets.

    This newly developed system helps take Phased Array Feed technology from a curious area of research to a highly efficient, multipurpose tool for exploring the universe.

    Commissioning observations with the National Science Foundation’s Green Bank Telescope (GBT) using this new design show that this instrument met and exceeded all testing goals. It also achieved the lowest operating noise temperature – a normally vexing problem for clear views of the sky — of any phased array receiver to date. This milestone is critical to move the technology from an experimental design to a fully fledged observing instrument.

    The results are published in The Astronomical Journal.

    “When looking at all phased array receiver technologies currently operating or in development, our new design clearly raises the bar and gives the astronomy community a new, more rapid way of conducting large-scale surveys,” said Anish Roshi, an astronomer-engineer with the National Radio Astronomy Observatory (NRAO) and a member of the design team.

    The new PAF was designed by a consortium of institutions: the NRAO’s Central Development Laboratory, Green Bank Observatory, and Brigham Young University.

    “The collaborative work that went into designing, building, and ultimately verifying this remarkable system is truly astounding,” said NRAO Director Tony Beasley. “It highlights the fact that new and emerging radio astronomy technology can have an immense impact on research.”

    The new PAF design consists of 19 dipole antennas, radio receivers that resemble miniature umbrellas without a covering. A dipole, which simply means “two poles,” is the most basic type of antenna. Its length determines the frequency — or wavelength of radio light — it is able to receive. In the PAF radio system, the strength of the signal can vary across the surface of the array. By calculating how the signal is received by each of the antennas, the system produces what is known as a “point-spread function” – essentially, a pattern of dots concentrated in one region.

    The PAF’s computer and signal processors can calculate up to seven point-spread functions at a time, enabling the receiver to synthesize seven individual beams on the sky. The new design also allows these regions to overlap, creating a more comprehensive view of the region of space being surveyed.

    “This project brings together in one instrument a state-of-the-art, low-noise receiver design, next generation multi-channel digital radio technology, and advanced phased array modeling and beamforming,” said Bill Shillue, PAF group lead at the NRAO’s Central Development Laboratory.

    The astronomical value of the receiver was demonstrated by GBT observations of the pulsar B0329+54 and the Rosette Nebula, a star-forming region of the Milky Way filled with ionized hydrogen gas.

    Additional development and computing power could enable this same design to generated an even greater number of beams on the sky, greatly expanding its utility.

    The National Radio Astronomy Observatory is a facility of the National Science Foundation, operated under cooperative agreement by Associated Universities, Inc.

    See the full article here.

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    NRAO/Karl V Jansky VLA, on the Plains of San Agustin fifty miles west of Socorro, NM, USA

    The NRAO operates a complementary, state-of-the-art suite of radio telescope facilities for use by the scientific community, regardless of institutional or national affiliation: the Very Large Array (VLA), and the Very Long Baseline Array (VLBA)*.

    ESO/NRAO/NAOJ ALMA Array in Chile in the Atacama at Chajnantor plateau, at 5,000 metres

    Access to ALMA observing time by the North American astronomical community will be through the North American ALMA Science Center (NAASC).

    NRAO VLBA

    NRAO VLBA

    *The Very Long Baseline Array (VLBA) comprises ten radio telescopes spanning 5,351 miles. It’s the world’s largest, sharpest, dedicated telescope array. With an eye this sharp, you could be in Los Angeles and clearly read a street sign in New York City!

    Astronomers use the continent-sized VLBA to zoom in on objects that shine brightly in radio waves, long-wavelength light that’s well below infrared on the spectrum. They observe blazars, quasars, black holes, and stars in every stage of the stellar life cycle. They plot pulsars, exoplanets, and masers, and track asteroids and planets.

    And the future Expanded Very Large Array (EVLA).

     
  • richardmitnick 1:34 pm on March 22, 2018 Permalink | Reply
    Tags: "Leading Arm" in the Magellanic Cloud swarf galaxies, , , , , GBO -Green Bank Observatory,   

    From Hubble: “Hubble Solves Cosmic ‘Whodunit’ with Interstellar Forensics” 

    NASA Hubble Banner

    NASA/ESA Hubble Telescope

    NASA/ESA Hubble Telescope

    Mar 22, 2018

    Ann Jenkins
    Space Telescope Science Institute, Baltimore, Maryland
    410-338-4488
    jenkins@stsci.edu

    Ray Villard
    Space Telescope Science Institute, Baltimore, Maryland
    410-338-4514
    villard@stsci.edu

    Andrew Fox
    Space Telescope Science Institute, Baltimore, Maryland
    410-338-5083
    afox@stsci.edu

    Image credits: D. Nidever et al., NRAO/AUI/NSF and A. Mellinger, Leiden-Argentine-Bonn (LAB) Survey, Parkes Observatory, Westerbork Observatory, Arecibo Observatory, and A. Feild (STScI)

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    Winner Declared in Tug-of-War Between Two Satellite Galaxies of the Milky Way
    In a cosmic tug-of-war between two dwarf galaxies orbiting the Milky Way, only NASA’s Hubble Space Telescope can see who’s winning. The players are the Large and Small Magellanic Clouds, and as they gravitationally tug at each other, one of them has pulled out a huge amount of gas from its companion.

    Large Magellanic Cloud. Adrian Pingstone December 2003

    Small Magellanic Cloud. NASA/ESA Hubble and ESO/Digitized Sky Survey 2

    This shredded and fragmented gas, called the Leading Arm, is being devoured by the Milky Way and feeding new star birth in our galaxy. But which dwarf galaxy is doing the pulling, and whose gas is now being feasted upon? Scientists used Hubble’s ultraviolet vision to chemically analyze the gas in the Leading Arm and determine its origin. After years of debate, we now have the answer to this “whodunit” mystery.

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    On the outskirts of our galaxy, a cosmic tug-of-war is unfolding—and only NASA’s Hubble Space Telescope can see who’s winning.

    The players are two dwarf galaxies, the Large Magellanic Cloud and the Small Magellanic Cloud, both of which orbit our own Milky Way Galaxy. But as they go around the Milky Way, they are also orbiting each other. Each one tugs at the other, and one of them has pulled out a huge cloud of gas from its companion.

    Called the Leading Arm, this arching collection of gas connects the Magellanic Clouds to the Milky Way. Roughly half the size of our galaxy, this structure is thought to be about 1 or 2 billion years old. Its name comes from the fact that it’s leading the motion of the Magellanic Clouds.

    The enormous concentration of gas is being devoured by the Milky Way and feeding new star birth in our galaxy. But which dwarf galaxy is doing the pulling, and whose gas is now being feasted upon? After years of debate, scientists now have the answer to this “whodunit” mystery.

    “There’s been a question: Did the gas come from the Large Magellanic Cloud or the Small Magellanic Cloud? At first glance, it looks like it tracks back to the Large Magellanic Cloud,” explained lead researcher Andrew Fox of the Space Telescope Science Institute in Baltimore, Maryland. “But we’ve approached that question differently, by asking: What is the Leading Arm made of? Does it have the composition of the Large Magellanic Cloud or the composition of the Small Magellanic Cloud?”

    Fox’s research is a follow-up to his 2013 work, which focused on a trailing feature behind the Large and Small Magellanic Clouds. This gas in this ribbon-like structure, called the Magellanic Stream, was found to come from both dwarf galaxies. Now Fox wondered about its counterpart, the Leading Arm. Unlike the trailing Magellanic Stream, this tattered and shredded “arm” has already reached the Milky Way and survived its journey to the galactic disk.

    The Leading Arm is a real-time example of gas accretion, the process of gas falling onto galaxies. This is very difficult to see in galaxies outside the Milky Way, because they are too far away and too faint. “As these two galaxies are in our backyard, we essentially have a front-row seat to view the action,” said collaborator Kat Barger at Texas Christian University.

    In a new kind of forensics, Fox and his team used Hubble’s ultraviolet vision to chemically analyze the gas in the Leading Arm. They observed the light from seven quasars, the bright cores of active galaxies that reside billions of light-years beyond this gas cloud. Using Hubble’s Cosmic Origins Spectrograph, the scientists measured how this light filters through the cloud.

    In particular, they looked for the absorption of ultraviolet light by oxygen and sulfur in the cloud. These are good gauges of how many heavier elements reside in the gas. The team then compared Hubble’s measurements to hydrogen measurements made by the National Science Foundation’s Robert C. Byrd Green Bank Telescope at the Green Bank Observatory in West Virginia, as well as several other radio telescopes.



    GBO radio telescope, Green Bank, West Virginia, USA

    “With the combination of Hubble and Green Bank Telescope observations, we can measure the composition and velocity of the gas to determine which dwarf galaxy is the culprit,” explained Barger.

    After much analysis, the team finally had conclusive chemical “fingerprints” to match the origin of the Leading Arm’s gas. “We’ve found that the gas matches the Small Magellanic Cloud,” said Fox. “That indicates the Large Magellanic Cloud is winning the tug-of-war, because it has pulled so much gas out of its smaller neighbor.”

    This answer was possible only because of Hubble’s unique ultraviolet capability. Because of the filtering effects of Earth’s atmosphere, ultraviolet light cannot be studied from the ground. “Hubble is the only game in town,” explained Fox. “All the lines of interest, including oxygen and sulfur, are in the ultraviolet. So if you work in the optical and infrared, you can’t see them.”

    Gas from the Leading Arm is now crossing the disk of our galaxy. As it crosses, it interacts with the Milky Way’s own gas, becoming shredded and fragmented.

    This is an important case study of how gas gets into galaxies and fuels star birth. Astronomers use simulations and try to understand the inflow of gas in other galaxies. But here, the gas is being caught red-handed as it moves across the Milky Way’s disk. Sometime in the future, planets and solar systems in our galaxy may be born out of material that used to be part of the Small Magellanic Cloud.

    The team’s study appears in the Feb. 20 issue of The Astrophysical Journal.
    As Fox and his team look ahead, they hope to map out the full size of the Leading Arm—something that is still unknown.

    Also see:
    Chemical Composition of Young Stars in the Leading Arm of the Magellanic System
    The Astrophysical Journal

    The Hubble Space Telescope is a project of international cooperation between NASA and ESA (European Space Agency). NASA’s Goddard Space Flight Center in Greenbelt, Maryland, manages the telescope. The Space Telescope Science Institute (STScI) in Baltimore, Maryland, conducts Hubble science operations. STScI is operated for NASA by the Association of Universities for Research in Astronomy, in Washington, D.C.

    See the full article here .

    Please help promote STEM in your local schools.

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    The Hubble Space Telescope is a project of international cooperation between NASA and the European Space Agency. NASA’s Goddard Space Flight Center manages the telescope. The Space Telescope Science Institute (STScI), is a free-standing science center, located on the campus of The Johns Hopkins University and operated by the Association of Universities for Research in Astronomy (AURA) for NASA, conducts Hubble science operations.

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    NASA image

     
  • richardmitnick 9:41 am on March 15, 2018 Permalink | Reply
    Tags: "little green men” Documentary Presentation, , , , , GBO -Green Bank Observatory,   

    From GBO: ““little green men” Documentary Presentation” 

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    Green Bank Radio Telescope, West Virginia, USA
    Green Bank Radio Telescope, West Virginia, USA

    gbo-sign

    Green Bank Observatory

    1
    Learn about the Pulsar Collaboratory Program that is enabling West Virginia high school students to use the Green Bank Telescopes in Pocahontas County to search for exotic stars called pulsars.

    “little green men” Documentary Presentation

    Enjoy a film documentary on the program followed by a discussion with film producers as well as astronomers and students involved in the program.

    Details

    Date:
    March 20
    Time:
    6:00 pm – 8:00 pm
    Event Category:
    Caperton Planetarium and Theater

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    All activities will take place in the Caperton Planetarium and Theater and are free to the public.
    304-561-3570 1 Clay Square | Charleston, WV 25301

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    gbo-science-building

    Mission Statement

    Green Bank Observatory enables leading edge research at radio wavelengths by offering telescope, facility and advanced instrumentation access to the astronomy community as well as to other basic and applied research communities. With radio astronomy as its foundation, the Green Bank Observatory is a world leader in advancing research, innovation, and education.

    History

    60 years ago, the trailblazers of American radio astronomy declared this facility their home, establishing the first ever National Radio Astronomy Observatory within the United States and the first ever national laboratory dedicated to open access science. Today their legacy is alive and well.

     
  • richardmitnick 9:43 pm on March 1, 2018 Permalink | Reply
    Tags: , , , , , GBO -Green Bank Observatory, NANOGrav-North American Nanohertz Observatory for Gravitational Waves, , ,   

    From GBO: “Pulsar Watchers Close In On Galaxy Merger History” 

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    Green Bank Radio Telescope, West Virginia, USA
    Green Bank Radio Telescope, West Virginia, USA

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    Green Bank Observatory

    2018-02-28
    Paul Vosteen

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    Astronomers see galaxies merging throughout the universe, some of which should result in binary supermassive black holes. Credit: NASA

    Fifty years after pulsar discovery published, massive new data set moves closer to finding very-low-frequency gravitational waves, researchers say.

    For the past twelve years, a group of astronomers have been watching the sky carefully, timing pulses of radio waves being emitted by rapidly spinning stars called pulsars, first discovered 50 years ago. These astronomers are interested in understanding pulsars, but their true goal is much more profound; the detection of a new kind of gravitational waves. With a new, more sophisticated analysis, they are much closer than ever before.

    Gravitational waves are wrinkles in space-time that stretch and squeeze the distances between objects. In 2015, a hundred years after Albert Einstein realized that accelerating massive objects should produce them, these waves were finally detected from black holes with masses roughly 30 times the mass of our sun colliding with each other. However, Einstein’s theory also predicts another kind of wave, one that comes from the mergers of black holes with masses of hundred million times the sun’s.

    Astronomers believe that nearly all galaxies have supermassive black holes at their centers. When two galaxies collide, these black holes will slowly fall toward each other, finally merging long after the initial galaxy collision. In the last stage of this process, as the two black holes spiral closer to each other, strong gravitational waves can be produced.

    While these waves travel at the speed of light, their strength varies quite slowly, on timescales ranging from months to years. This means that gravitational wave observatories on Earth can’t measure them. For that, you need an observatory with detectors light-years apart.

    “We know that galaxy mergers are an important part of galaxy growth and evolution through cosmic time. By detecting gravitational waves from supermassive binary black holes at the cores of merging galaxies, we will be able to probe how galaxies are shaped by those black holes,” said Sarah Burke-Spolaor, assistant professor at West Virginia University.

    2
    Nature publication of the discovery of pulsar B1919+21. Credit: Reproduced by permission from Springer Nature

    Fifty years ago, the February 24, 1968 edition of the journal Nature provided the solution, with the discovery of a new kind of star. This new star was curious, emitting regular radio pulses once every 1.3 seconds. Graduate student Jocelyn Bell (now Dr. Bell Burnell [now really Dame Susan Jocelyn Bell Burnell, one of the many women denied a deserved Nobel]) was the first to spot the signal, seeing it as “a bit of scruff” in her radio surveys. Zooming in on the scruff, Bell saw the regular pulses from the star.

    After first entertaining the possibility that the pulses could be the result of LGM, or “little green men,” the new star was dubbed a pulsar, with the understanding that the pulses represented the rotation rate of the star. Such a rapid rotation rate meant that the star must be small, about the size of a city. Only a few years later, a pulsar in a binary system was found, and the first mass estimate indicated that this tiny object held about one and a half times the mass of our sun.

    “Before this time, no one thought stars so small could actually exist! It wasn’t until a pulsar was found at the center of a supernova remnant in 1968 that astronomers realized that pulsars were neutron stars born in the explosions of massive stars,” said Maura McLaughlin, professor at West Virginia University.

    4
    After detecting unexpected signals at the same location in the sky (top left), graduate student Jocelyn Bell (right) [now Dame Susan Jocelyn Bell Burnell] observed individual pulses from the new source (bottom left) in late 1967. Credit: UK National Science & Media Museum

    6
    2009 Dame Susan Jocelyn Bell Burnell. Wikipedia

    The fastest pulsars, called millisecond pulsars, spin hundreds of times every second (faster than your kitchen blender!), and are the most stable natural clocks known in the universe. Pulsar astronomers around the globe are monitoring these stellar clocks in order to form a new kind of cosmic gravitational wave detector known as a “Pulsar Timing Array.” By carefully measuring when radio pulses arrive from millisecond pulsars, astronomers can track the tiny changes in the distance from the Earth to the pulsars caused by the stretching and squeezing of spacetime due to a gravitational wave.

    In the US and Canada, a group called NANOGrav (North American Nanohertz Observatory for Gravitational Waves) is searching for these gravitational waves using some of the largest telescopes in the world, including the Green Bank Telescope in West Virginia and the Arecibo Observatory in Puerto Rico.

    NAIC/Arecibo Observatory, Puerto Rico, USA, at 497 m (1,631 ft)

    NANOGrav routinely joins forces with groups in Europe and Australia to improve their sky coverage and sensitivity. Collectively known as the International Pulsar Timing Array, the combined observations from these groups constitute the most sensitive data set in the world for searching for low-frequency gravitational waves.

    6
    International Pulsar Timing Array

    This month, fifty years after the publication of the first pulsar discovery, NANOGrav has submitted a pair of companion papers to The Astrophysical Journal describing eleven years of monthly observations of 45 millisecond pulsars along with the astrophysical implications of their results. For the first time, the data set includes a six-pulsar “high-frequency” sample, with measurements made every week to expand the pulsar timing array’s sensitivity range. NANOGrav is able to set sensitive upper limits that constrain the physical processes at play in galaxy mergers. As their sensitivity improves, NANOGrav is uncovering new sources of background noise that must be accounted for. Most recently, uncertainties in the pull of Jupiter on the sun have been found to affect pulsar timing. As a result, the team is implementing new computational methods to account for this, in effect determining Jupiter’s orbit more precisely than possible except by planetary missions.

    “This is the most sensitive pulsar timing dataset ever created for both gravitational wave analysis and a host of other astrophysical measurements. And with each new release, we will add more pulsars and data, which increase our sensitivity to gravitational waves”, said David Nice, professor at Lafayette College.

    Last year, the journal that announced the discovery of pulsars once again played host to a pulsar first. In November, Nature Astronomy published their first-ever article describing the gravitational wave environment that pulsar timing arrays are working to uncover. By looking at galaxy surveys, the article estimates there are about 100 supermassive black hole binaries that are close enough to affect pulsar timing array measurements. Given their expected future sensitivity, the authors state that pulsar timing arrays should be able to isolate the gravitational waves from a specific individual galaxy within about 10 years.

    “From city-sized pulsars spinning fast in galaxies to large, massive galaxies themselves and their merging central black holes, all in 50 years! That is a large step for humankind, and not one that we could have foreseen. What will the next 50 years bring? Pulsars and gravitational waves will continue to be big news, I’m sure!” said Jocelyn Bell Burnell.

    A century after Einstein first predicted them, gravitational waves were finally detected. Now, 50 years after Jocelyn Bell’s discovery, pulsars have become a new tool for measuring both gravitational waves and the distant black holes that create them. If predictions are correct, the next decade will be an exciting period of discovery for radio astronomers, pulsars, and gravitational waves!

    Links to supporting materials:
    1-page summary of 11-year results: https://nanograv.github.io/11yr_stochastic_analysis/ Submitted to the Astrophysical Journal, Dec 31, 2017

    11-Year Data Release paper: https://arxiv.org/abs/1801.01837 Submitted to The Astrophysical Journal

    Gravitational Wave Search paper: https://arxiv.org/abs/1801.02617 Submitted to The Astrophysical Journal

    See the full article here .

    Please help promote STEM in your local schools.

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    Mission Statement

    Green Bank Observatory enables leading edge research at radio wavelengths by offering telescope, facility and advanced instrumentation access to the astronomy community as well as to other basic and applied research communities. With radio astronomy as its foundation, the Green Bank Observatory is a world leader in advancing research, innovation, and education.

    History

    60 years ago, the trailblazers of American radio astronomy declared this facility their home, establishing the first ever National Radio Astronomy Observatory within the United States and the first ever national laboratory dedicated to open access science. Today their legacy is alive and well.

     
  • richardmitnick 7:48 am on February 7, 2018 Permalink | Reply
    Tags: Astronomers peer into the lair of a mysterious source of cosmic radio bursts, , , , , , GBO -Green Bank Observatory, ,   

    From GBO: “Astronomers peer into the lair of a mysterious source of cosmic radio bursts” 

    gbo-logo

    Green Bank Radio Telescope, West Virginia, USA
    Green Bank Radio Telescope, West Virginia, USA

    gbo-sign

    Green Bank Observatory

    2018-01-10
    Paul Vosteen
    Media Specialist; Education & Public Outreach
    Green Bank Observatory
    +1.304.456.2212
    pvosteen@nrao.edu

    Contact:
    Dr. Jason Hessels, University of Amsterdam, Anton Pannekoek Institute for Astronomy / ASTRON – Netherlands Institute for Radio Astronomy
    E-mail: J.W.T.Hessels@uva.nl
    Tel: +31 (0)610260062

    Daniele Michilli, University of Amsterdam, Anton Pannekoek Institute for Astronomy / ASTRON – Netherlands Institute for Radio Astronomy
    E-mail: danielemichilli@gmail.com

    Dr. Andrew Seymour, National Astronomy and Ionosphere Center Arecibo Observatory, Puerto Rico
    E-mail: seymour.andrew@gmail.com

    Dr. Laura Spitler, Max-Planck-Institute for Radioastronomy, Bonn, Germany
    E-mail: lspitler@mpifr-bonn.mpg.de

    Dr. Shami Chatterjee, Cornell University
    Tel: +1 (607) 279 2076
    E-mail: shami@astro.cornell.edu

    Dr. Ryan Lynch, Green Bank Observatory
    Tel: 1+ (304) 456 2357
    E-mail: rlynch@nrao.edu

    1
    Artist concept of fast radio burst. Image Credit: Design: Danielle Futselaar; photo usage: shutterstock.com

    Using two of the world’s largest radio telescopes, an international team of astronomers have gained new insight into the extreme home of a mysterious source of cosmic radio bursts. The discovery suggests that the source of the radio emission lies near a massive black hole or within an extremely powerful nebula, and may help shed light on what is causing these strange bursts.

    The team presented their findings at the American Astronomical Society’s winter meeting (#AAS231) in Washington, D.C. The results are presented in the journal Nature.

    Using data from the Arecibo Observatory in Puerto Rico and the Green Bank Telescope in West Virginia, researchers have shown that the radio bursts from an object known as FRB121102 have a property known as polarization, and are “twisted” through a process called Faraday rotation.

    NAIC/Arecibo Observatory, Puerto Rico, USA, at 497 m (1,631 ft)

    “I couldn’t believe my eyes when I first saw the data. Such extreme Faraday rotation is unprecedented,” says Jason Hessels of the University of Amsterdam and ASTRON (Netherlands Institute for Radio Astronomy), the leader of the team.

    FRB121102 is an example of a fast radio burst (FRB) – a mysterious and very short flash of radio waves emanating from deep in extragalactic space. The home galaxy of FRB121102 is located 3 billion light-years from Earth; at this distance, the bursts must be nearly 100 million times more powerful than the Sun to be seen from Earth. The cause of FRBs is one of the biggest mysteries in astronomy today. “FRB 121102 was already unique because it repeats, which hasn’t yet been observed in any other FRBs; now the huge Faraday rotation we have detected singles it out yet again. We’re curious as to whether these two unique aspects are linked,” says Daniele Michilli, a PhD candidate at the University of Amsterdam and ASTRON (Netherlands Institute for Radio Astronomy).

    Faraday rotation occurs when polarized light travels through a strongly magnetized, hot gas known as plasma. Faraday rotation this strong has not been found anywhere else in the Universe, though the conditions near the black hole that lies at the center of Earth’s own Milky Way galaxy come close. This leads researchers to propose that FRB121102 could be located near a massive black hole of its own, or embedded within the remains of a dead star.

    Key to the discovery was detecting the bursts at a higher radio frequency than ever before. “At the Arecibo Observatory, we developed a new observing setup and additional hardware that allowed us to observe at these higher frequencies,” says Andrew Seymour, staff astronomer at the National Astronomy and Ionosphere Center, which operates Arecibo. “What’s more, one of the bursts we detected lasted less than 30 microseconds. Such a short duration argues that the bursts originate from a neutron star in an extreme environment of magnetized plasma,” he adds.

    “Our partners in the Breakthrough Listen project were able to use the Green Bank Telescope and a fantastic new instrument that they built to observe this source over the widest range of radio frequencies to-date, confirming what had been seen at Arecibo Observatory. It’s such a surprising result, so this was a really important step in convincing everyone that this unprecedented degree of Faraday rotation is real,” explains Ryan Lynch, a staff scientist at the Green Bank Observatory.

    As a fun way of visualizing the shapes of the bursts, team member Anne Archibald (University of Amsterdam) has made 3D printed models, which show the brightness of each burst as a function of both time and the observed radio frequency. These designs are freely available for download at https://www.thingiverse.com/thing:2723399.

    In future research, the astronomers hope to distinguish between the two leading hypotheses – either a neutron star near a black hole or one embedded in a powerful nebula – or possibly other, more exotic interpretations, by monitoring how the Faraday rotation and other properties of the bursts change with time. With a number of wide-field radio telescopes now coming online, more such sources are expected to be discovered in the coming year, and astronomers are poised to answer more fundamental questions about FRBs.

    See the full article here .

    Please help promote STEM in your local schools.

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    Stem Education Coalition

    gbo-science-building

    Mission Statement

    Green Bank Observatory enables leading edge research at radio wavelengths by offering telescope, facility and advanced instrumentation access to the astronomy community as well as to other basic and applied research communities. With radio astronomy as its foundation, the Green Bank Observatory is a world leader in advancing research, innovation, and education.

    History

    60 years ago, the trailblazers of American radio astronomy declared this facility their home, establishing the first ever National Radio Astronomy Observatory within the United States and the first ever national laboratory dedicated to open access science. Today their legacy is alive and well.

     
  • richardmitnick 8:52 pm on January 10, 2018 Permalink | Reply
    Tags: , , , , GBO -Green Bank Observatory, Swarm of Hydrogen Clouds Flying Away from Center of our Galaxy   

    From GBO: “Swarm of Hydrogen Clouds Flying Away from Center of our Galaxy” 

    gbo-logo

    Green Bank Radio Telescope, West Virginia, USA
    Green Bank Radio Telescope, West Virginia, USA

    gbo-sign

    Green Bank Observatory

    Contact:
    Mike Holstine
    Business Manager, Green Bank Observatory
    +1 (304) 456-2011
    michaelholstine@gbobservatory.org

    2018-01-10
    Paul Vosteen

    1
    Photo Source: S. Brunier; Design & Illustration: P. Vosteen

    A team of astronomers has discovered what appears to be a grand exodus of more than 100 hydrogen clouds streaming away from the center of the Milky Way and heading into intergalactic space. This observation, made with the National Science Foundation’s Green Bank Telescope (GBT), may give astronomers a clearer picture of the so-called Fermi Bubbles, giant balloons of superheated gas billowing out above and below the disk of our galaxy.

    The results are presented today at the 231st meeting of the American Astronomical Society in Washington, D.C.

    “The center of the Milky Way is a special place,” notes Jay Lockman, an astronomer at the Green Bank Observatory in West Virginia. “At its heart is a black hole several million times more massive than the Sun and there are regions of intense star birth and explosive star destruction.”

    These energetic processes, perhaps individually or together, have generated a powerful cosmic “wind” that has blown two enormous bubbles above and below the disk of the Milky Way that are filled with gas at tens-of-millions of degrees. This superheated gas, however, shines feebly at radio, X-ray and gamma-ray wavelengths.

    The bubbles appear prominently in observations made by NASA’s Fermi Gamma-ray Space Telescope, which is why astronomers refer to them as the Fermi Bubbles.

    NASA/Fermi Gamma Ray Space Telescope

    “One problem that hinders study of this hot cosmic wind is that the gas has such low density that its emission is very faint, so there is no practical way to track its motion,” notes Lockman. “This is where the hydrogen clouds come in.”

    Just like a handful of dust thrown into the air can show the motion of wind on Earth, the hydrogen clouds can act as test particles revealing the flow of the hotter, invisible wind from the center of the Milky Way.

    Neutral hydrogen gas, the principal component of these clouds, shines brightly at the radio wavelength of 21 centimeters. These hydrogen clouds were first discovered by a team led by Naomi McClure-Griffiths of the Australian National University using a radio telescope array in Australia. However, that survey was confined to a region just a few degrees around the galactic center, so it gave only limited information on the number and extent of these clouds.

    New research with the 100-meter GBT greatly extends these observations.

    A group led by Lockman, McClure-Griffiths, and Enrico DiTeodoro, who is also with the Australian National University, mapped a much larger area around the galactic center in search of additional hydrogen clouds that might be entrained in the nuclear wind. They found a gigantic swarm of more than 100 high-velocity gas clouds. The properties of these clouds allow the scientists to learn about the shape of the wind-blown region and the enormous energies that are involved.

    “The signature of these clouds being blown out of the Milky Way is that their velocities are crazy,” said Lockman. “Gas motions in the Milky Way are usually quite regular and are dominated by the orderly rotation of the Galaxy. In the Fermi Bubbles we see clouds right next to each other on the sky that have velocities differing by as much as 400 kilometers per second.”

    According to the researchers, the most likely explanation for these wildly differing velocities is that they’re traveling within a cone of material that is expanding upward and away from the galactic center, so the front portion is coming toward us and the back part is flying away.

    By modeling the distribution and velocities of the clouds, the astronomers found that they would fill a cone stretching above and below the galaxy to a distance of at least 5,000 light-years from the center. The clouds have an average speed of about 330 kilometers per second.

    Di Teodoro notes: “What is especially puzzling is that we have not yet found the edge of the swarm of clouds. Somewhere above the galactic center, the hydrogen clouds have to dissipate or become ionized. But we have not found that edge yet, so there’s still a lot to learn.”

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    gbo-science-building

    Mission Statement

    Green Bank Observatory enables leading edge research at radio wavelengths by offering telescope, facility and advanced instrumentation access to the astronomy community as well as to other basic and applied research communities. With radio astronomy as its foundation, the Green Bank Observatory is a world leader in advancing research, innovation, and education.

    History

    60 years ago, the trailblazers of American radio astronomy declared this facility their home, establishing the first ever National Radio Astronomy Observatory within the United States and the first ever national laboratory dedicated to open access science. Today their legacy is alive and well.

     
  • richardmitnick 11:54 am on August 31, 2017 Permalink | Reply
    Tags: Berkeley SETI Research Center, , , GBO -Green Bank Observatory,   

    From UC Berkeley: “Distant galaxy sends out 15 high-energy radio bursts” 

    UC Berkeley

    UC Berkeley

    August 30, 2017
    Robert Sanders
    rlsanders@berkeley.edu

    Breakthrough Listen, an initiative to find signs of intelligent life in the universe, has detected 15 brief but powerful radio pulses emanating from a mysterious and repeating source – FRB 121102 – far across the universe.

    Breakthrough Listen Project

    Fast radio bursts are brief, bright pulses of radio emission from distant but largely unknown sources, and FRB 121102 is the only one known to repeat: more than 150 high-energy bursts have been observed coming from the object, which was identified last year as a dwarf galaxy about 3 billion light years from Earth.

    2
    A sequence of 14 of the 15 detected bursts illustrate their dispersed spectrum and extreme variability. The streaks across the colored energy plot are the bursts appearing at different times and different energies because of dispersion caused by 3 billion years of travel through intergalactic space. In the top frequency spectrum, the dispersion has been removed to show the 300 microsecond pulse spike. Capturing this diverse set of bursts was made possible by the broad bandwidth that can be processed by the Breakthrough Listen backend at the Green Bank Telescope.



    GBO radio telescope, Green Bank, West Virginia, USA

    Possible explanations for the repeating bursts range from outbursts from rotating neutron stars with extremely strong magnetic fields – so-called magnetars – to a more speculative idea: They are directed energy sources, powerful laser bursts used by extraterrestrial civilizations to power spacecraft, akin to Breakthrough Starshot’s plan to use powerful laser pulses to propel nano-spacecraft to our solar system’s nearest star, Proxima Centauri.

    Breakthrough Starshot

    “Bursts from this source have never been seen at this high a frequency,” said Andrew Siemion, director of the Berkeley SETI Research Center and of the Breakthrough Listen program.

    As astronomers around the globe try to understand the mechanism generating fast radio bursts, they have repeatedly turned their radio telescopes on FRB 121102. Siemion and his team alerted the astronomical community to the high-frequency activity via an Astronomer’s Telegram on Monday evening, Aug. 28.

    “As well as confirming that the source is in a newly active state, the high resolution of the data obtained by the Listen instrument will allow measurement of the properties of these mysterious bursts at a higher precision than ever possible before,” said Breakthrough Listen postdoctoral researcher Vishal Gajjar, who discovered the increased activity.

    First detected with the Parkes Telescope in Australia, fast radio bursts have now been seen by several radio telescopes around the world.

    CSIRO/Parkes Observatory, located 20 kilometres north of the town of Parkes, New South Wales, Australia

    FRB 121102 was discovered on Nov. 2, 2012, (hence its name) and in 2015 it was the first fast radio burst seen to repeat, ruling out theories of bursts’ origins that involved the catastrophic destruction of the progenitor, at least in this instance.

    Regardless of FRB 121102’s ultimate source, when the recently detected pulses left their host galaxy, our solar system was less than 2 billion years old, noted Steve Croft, a Breakthrough Listen astronomer at UC Berkeley. Life on Earth consisted only of single-celled organisms; it would be another billion years before even the simplest multi-cellular life began to evolve.

    As part of Breakthrough Listen’s program to observe nearby stars and galaxies for signatures of extraterrestrial technology, the project science team at UC Berkeley added FRB 121102 to its list of targets. In the early hours of Saturday, Aug. 26, Gajjar observed that area of the sky using the Breakthrough Listen backend instrument at the Green Bank Telescope in West Virginia.

    The instrument accumulated 400 terabytes (a million million bytes) of data over a five-hour period, observing across the entire 4 to 8 GHz frequency band. This large dataset was searched for signatures of short pulses from the source over a broad range of frequencies, with a characteristic dispersion, or delay as a function of frequency, caused by the presence of gas in space between Earth and the source. The distinctive shape that the dispersion imposes on the initial pulse is an indicator of the amount of material between us and the source, and hence an indicator of the distance to the host galaxy.

    Analysis by Gajjar and the Breakthrough Listen team revealed 15 new pulses from FRB 121102. The observations show for the first time that fast radio bursts emit at higher frequencies than previously observed, with the brightest emission occurring at around 7 GHz.

    “The extraordinary capabilities of the backend receiver, which is able to record several gigahertz of bandwidth at a time, split into billions of individual channels, enable a new view of the frequency spectrum of FRBs, and should shed additional light on the processes giving rise to FRB emission.” Gajjar said.

    “Whether or not fast radio bursts turn out to be signatures of extraterrestrial technology, Breakthrough Listen is helping to push the frontiers of a new and rapidly growing area of our understanding of the universe around us,” Siemion said.

    See the full article here .
    Previously noted briefly here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    Founded in the wake of the gold rush by leaders of the newly established 31st state, the University of California’s flagship campus at Berkeley has become one of the preeminent universities in the world. Its early guiding lights, charged with providing education (both “practical” and “classical”) for the state’s people, gradually established a distinguished faculty (with 22 Nobel laureates to date), a stellar research library, and more than 350 academic programs.

    UC Berkeley Seal

     
  • richardmitnick 3:46 pm on July 19, 2017 Permalink | Reply
    Tags: , , , GBO -Green Bank Observatory, , , , , U Chicago Yerkes Observatory   

    From Centauri Dreams: “Keeping an Eye on Ross 128” 

    Centauri Dreams

    July 19, 2017
    Paul Gilster

    1
    A screen shot from Abel Méndez’s lab note titled “Strange Signals from the Nearby Red Dwarf Star Ross 128.” Credit: Planetary Habitability Laboratory/University of Puerto Rico, Arecibo/Aladin Sky Atlas.

    Frank Elmore Ross (1874-1960), an American astronomer and physicist, became the successor to E. E. Barnard at Yerkes Observatory.

    1
    U Chicago Yerkes Observatory

    2
    U Chicago Yerkes Observatory interior

    Barnard, of course, is the discoverer of the high proper motion of the star named after him, alerting us to its proximity.

    3
    http://www.daviddarling.info/encyclopedia/B/BarnardsStar.html

    And as his successor, Ross would go on to catalog over 1000 stars with high proper motion, many of them nearby. Ross 128, now making news for what observers at the Arecibo Observatory are calling “broadband quasi-periodic non-polarized pulses with very strong dispersion-like features,” is one of these, about 11 light years out in the direction of Virgo.

    NAIC/Arecibo Observatory, Puerto Rico, USA

    Any nearby stars are of interest from the standpoint of exoplanet investigations, though thus far we’ve yet to discover any companions around Ross 128. An M4V dwarf, Ross 128 has about 15 percent of the Sun’s mass. More significantly, it is an active flare star, capable of unpredictable changes in luminosity over short periods. Which leads me back to that unusual reception. The SETI Institute’s Seth Shostak described it this way in a post:

    “What the Puerto Rican astronomers found when the data were analyzed was a wide-band radio signal. This signal not only repeated with time, but also slid down the radio dial, somewhat like a trombone going from a higher note to a lower one.”

    And as Shostak goes on to say, “That was odd, indeed.”

    It’s this star’s flare activity that stands out for me as I look over the online announcement of its unusual emissions, which were noted during a ten-minute spectral observation at Arecibo on May 12. Indeed, Abel Mendez, director of the Planetary Habitability Laboratory at Arecibo, cited Type II solar flares first in a list of possible explanations, though his post goes on to note that such flares tend to occur at lower frequencies. An additional novelty is that the dispersion of the signal points to a more distant source, or perhaps to unusual features in the star’s atmosphere. All of this leaves a lot of room for investigation.

    We also have to add possible radio frequency interference (RFI) into the mix, something the scientists at Arecibo are examining as observations continue. The possibility that we are dealing with a new category of M-dwarf flare is intriguing and would have obvious ramifications given the high astrobiological interest now being shown in these dim red stars.

    All of this needs to be weighed as we leave the SETI implications open. The Arecibo post notes that signals from another civilization are “at the bottom of many other better explanations,” as well they should be assuming those explanations pan out. But we should also keep our options open, which is why the news that the Breakthrough Listen initiative has now observed Ross 128 with the Green Bank radio telescope in West Virginia is encouraging.



    GBO radio telescope, Green Bank, West Virginia, USA

    No evidence of the emissions Arecibo detected has turned up in the Breakthrough Listen data. We’re waiting for follow-up observations from Arecibo, which re-examined the star on the 16th, and Mendez in an update noted that the SETI Institute’s Allen Telescope Array had also begun observations.

    SETI/Allen Telescope Array situated at the Hat Creek Radio Observatory, 290 miles (470 km) northeast of San Francisco, California, USA

    Seth Shostak tells us that the ATA has thus far collected more than 10 hours of data, observations which may help us determine whether the signal has indeed come from Ross 128 or has another source.

    “We need to get all the data from the other partner observatories to put all things together for a conclusion,” writes Mendez. “Probably by the end of this week.”
    [Shostak]

    Or perhaps not, given the difficulty of detecting the faint signal and the uncertainties involved in characterizing it. If you’re intrigued, an Arecibo survey asking for public reactions to the reception is now available.

    I also want to point out that Arecibo Observatory is working on a new campaign to observe stars like Ross 128, the idea being to characterize their magnetic environment and radiation. One possible outcome of work like that is to detect perturbations in their emissions that could point to planets — planetary magnetic fields could conceivably affect flare activity. That’s an intriguing way to look for exoplanets, and the list being observed includes Barnard’s Star, Gliese 436, Ross 128, Wolf 359, HD 95735, BD +202465, V* RY Sex, and K2-18.

    A final note: Arecibo is now working with the Red Dots campaign in coordination with other observatories to study Barnard’s Star, for which there is some evidence of a super-Earth mass planet. More on these observations can be found in this Arecibo news release.

    ESO Red Dots Campaign

    Centauri Dreams


    See the full article here .

    Please help promote STEM in your local schools.

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    Stem Education Coalition

    Tracking Research into Deep Space Exploration

    Alpha Centauri and other nearby stars seem impossible destinations not just for manned missions but even for robotic probes like Cassini or Galileo. Nonetheless, serious work on propulsion, communications, long-life electronics and spacecraft autonomy continues at NASA, ESA and many other venues, some in academia, some in private industry. The goal of reaching the stars is a distant one and the work remains low-key, but fascinating ideas continue to emerge. This site will track current research. I’ll also throw in the occasional musing about the literary and cultural implications of interstellar flight. Ultimately, the challenge may be as much philosophical as technological: to reassert the value of the long haul in a time of jittery short-term thinking.

     
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