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  • richardmitnick 11:06 am on August 6, 2019 Permalink | Reply
    Tags: "Geoengineering versus a volcano", , Carnegie Institution For Science, , ,   

    From Carnegie Institution for Science: “Geoengineering versus a volcano” 

    Carnegie Institution for Science
    From Carnegie Institution for Science

    August 05, 2019

    1
    A photo of the eruption of Mount Pinatubo by Jackson K., courtesy of USGS.

    Major volcanic eruptions spew ash particles into the atmosphere, which reflect some of the Sun’s radiation back into space and cool the planet. But could this effect be intentionally recreated to fight climate change? A new paper in Geophysical Research Letters investigates.

    Solar geoengineering is a theoretical approach to curbing the effects of climate change by seeding the atmosphere with a regularly replenished layer of intentionally released aerosol particles. Proponents sometimes describe it as being like a “human-made” volcano.

    “Nobody likes the idea of intentionally tinkering with our climate system at global scale,” said Carnegie’s Ken Caldeira. “Even if we hope these approaches won’t ever have to be used, it is really important that we understand them because someday they might be needed to help alleviate suffering.”

    He, along with Carnegie’s Lei Duan (a former student from Zhejiang University), Long Cao of Zhejiang University, and Govindasamy Bala of the Indian Institute of Science, set out to compare the effects on the climate of a volcanic eruption and of solar geoengineering. They used sophisticated models to investigate the impact of a single volcano-like event, which releases particulates that linger in the atmosphere for just a few years, and of a long-term geoengineering deployment, which requires maintaining an aerosol layer in the atmosphere.

    They found that regardless of how it got there, when the particulate material is injected into the atmosphere, there is a rapid decrease in surface temperature, with the land cooling faster than the ocean.

    However, the volcanic eruption created a greater temperature difference between the land and sea than did the geoengineering simulation. This resulted in different precipitation patterns between the two scenarios. In both situations, precipitation decreases over land—meaning less available water for many people living there—but the decrease was more significant in the aftermath of a volcanic eruption than it was in the geoengineering case.

    “When a volcano goes off, the land cools substantially quicker than the ocean. This disrupts rainfall patterns in ways that you wouldn’t expect to happen with a sustained deployment of a geoengineering system,” said lead author Duan.

    Overall, the authors say that their results demonstrate that volcanic eruptions are imperfect analogs for geoengineering and that scientists should be cautious about extrapolating too much from them.

    “While it’s important to evaluate geoengineering proposals from an informed position, the best way to reduce climate risk is to reduce emissions,” Caldeira concluded.

    See the full article here .


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    Please help promote STEM in your local schools.

    Stem Education Coalition

    Carnegie Institution of Washington Bldg

    Carnegie Institution for Science

    Andrew Carnegie established a unique organization dedicated to scientific discovery “to encourage, in the broadest and most liberal manner, investigation, research, and discovery and the application of knowledge to the improvement of mankind…” The philosophy was and is to devote the institution’s resources to “exceptional” individuals so that they can explore the most intriguing scientific questions in an atmosphere of complete freedom. Carnegie and his trustees realized that flexibility and freedom were essential to the institution’s success and that tradition is the foundation of the institution today as it supports research in the Earth, space, and life sciences.

    6.5 meter Magellan Telescopes located at Carnegie’s Las Campanas Observatory, Chile.
    6.5 meter Magellan Telescopes located at Carnegie’s Las Campanas Observatory, Chile


    Carnegie Las Campanas 2.5 meter Irénée Dupont telescope, Atacama Desert, over 2,500 m (8,200 ft) high approximately 100 kilometres (62 mi) northeast of the city of La Serena,Chile


    Carnegie Institution Swope telescope at Las Campanas, Chile, 100 kilometres (62 mi) northeast of the city of La Serena. near the north end of a 7 km (4.3 mi) long mountain ridge. Cerro Las Campanas, near the southern end and over 2,500 m (8,200 ft) high, at Las Campanas, Chile

    [/caption]

     
  • richardmitnick 1:28 pm on July 30, 2019 Permalink | Reply
    Tags: "Study reveals new structure of gold at extremes", , , Carnegie Institution For Science, Increase in pressure and temperature changes the crystalline structure to a new phase of gold., , ,   

    From Lawrence Livermore National Laboratory: “Study reveals new structure of gold at extremes” 

    From Lawrence Livermore National Laboratory

    July 30, 2019
    Breanna Bishop
    bishop33@llnl.gov
    925-423-9802

    1
    Three of the images collected at Argonne National Laboratory’s Dynamic Compression Sector, highlighting diffracted signals recorded on the X-ray detector.

    Section 1 shows the starting face-centered cubic structure; Section 2 shows the new body-centered cubic structure at 220 GPa; and Section 3 shows the liquid gold at 330 GPa.

    Gold is an extremely important material for high-pressure experiments and is considered the “gold standard” for calculating pressure in static diamond anvil cell experiments. When compressed slowly at room temperature (on the order of seconds to minutes), gold prefers to be the face-centered cubic (fcc) structure at pressures up to three times the center of the Earth.

    However, researchers from Lawrence Livermore National Laboratory (LLNL) and the Carnegie Institution for Science have found that when gold is compressed rapidly over nanoseconds (1 billionth of a second), the increase in pressure and temperature changes the crystalline structure to a new phase of gold.

    This well-known body-centered cubic (bcc) structure morphs to a more open crystal structure than the fcc structure. These results were published recently in Physical Review Letters.

    “We discovered a new structure in gold that exists at extreme states — two thirds of the pressure found at the center of Earth,” said lead author Richard Briggs, a postdoctoral researcher at LLNL. “The new structure actually has less efficient packing at higher pressures than the starting structure, which was surprising considering the vast amount of theoretical predictions that pointed to more tightlypacked structures that should exist.”

    The experiments were carried out at the Dynamic Compression Sector (DCS) at the Advanced Photon Source, Argonne National Laboratory.

    ANL Advanced Photon Source

    DCS is the first synchrotron X-ray facility dedicated to dynamic compression science. These user experiments were some of the first conducted on hutch-C, the dedicated high energy laser station of DCS. Gold was the ideal subject to study due to its high-Z (providing a strong X-ray scattering signal) and relatively unexplored phase diagram at high temperatures.

    The team found that that the structure of gold began to change at a pressure of 220 GPa (2.2 million times Earth’s atmospheric pressure) and started to melt when compressed beyond 250 GPa.

    “The observation of liquid gold at 330 GPa is astonishing,” Briggs said. “This is the pressure at the center of the Earth and is more than 300 GPa higher than previous measurements of liquid gold at high pressure.”

    The transition from fcc to bcc structure is perhaps one of the most studied phase transitions due to its importance in the manufacturing of steel, where high temperatures or stress causes a change in structure between the two fcc/bcc structures. However, it is not known what phase transition mechanism is responsible. The research team’s results show that gold undergoes the same phase transition before it melts, as a consequence of both pressure and temperature, and future experiments focusing on the mechanism of the transition can help clarify key details of this important transition for manufacturing strong steels.

    “Many of the theoretical models of gold that are used to understand the high-pressure/high-temperature behavior did not predict the formation of a body-centered structure – only two out of more than 10 published works,” Briggs said. “Our results can help theorists improve their models of elements under extreme compression and look toward using those new models to examine the effects of chemical bonding to aid the development of new materials that can be formed at extreme states.”

    Briggs was joined on the publication by co-authors Federica Coppari, Martin Gorman, Ray Smith, Amy Coleman, Amalia Fernandez-Panella, Marius Millot, Jon Eggert and Dane Fratanduono from LLNL, and Sally Tracy from the Carnegie Institution of Washington’s Geophysical Laboratory.

    See the full article here .


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    Please help promote STEM in your local schools.

    Stem Education Coalition

    LLNL Campus

    Operated by Lawrence Livermore National Security, LLC, for the Department of Energy’s National Nuclear Security Administration
    Lawrence Livermore National Laboratory (LLNL) is an American federal research facility in Livermore, California, United States, founded by the University of California, Berkeley in 1952. A Federally Funded Research and Development Center (FFRDC), it is primarily funded by the U.S. Department of Energy (DOE) and managed and operated by Lawrence Livermore National Security, LLC (LLNS), a partnership of the University of California, Bechtel, BWX Technologies, AECOM, and Battelle Memorial Institute in affiliation with the Texas A&M University System. In 2012, the laboratory had the synthetic chemical element livermorium named after it.
    LLNL is self-described as “a premier research and development institution for science and technology applied to national security.” Its principal responsibility is ensuring the safety, security and reliability of the nation’s nuclear weapons through the application of advanced science, engineering and technology. The Laboratory also applies its special expertise and multidisciplinary capabilities to preventing the proliferation and use of weapons of mass destruction, bolstering homeland security and solving other nationally important problems, including energy and environmental security, basic science and economic competitiveness.

    The Laboratory is located on a one-square-mile (2.6 km2) site at the eastern edge of Livermore. It also operates a 7,000 acres (28 km2) remote experimental test site, called Site 300, situated about 15 miles (24 km) southeast of the main lab site. LLNL has an annual budget of about $1.5 billion and a staff of roughly 5,800 employees.

    LLNL was established in 1952 as the University of California Radiation Laboratory at Livermore, an offshoot of the existing UC Radiation Laboratory at Berkeley. It was intended to spur innovation and provide competition to the nuclear weapon design laboratory at Los Alamos in New Mexico, home of the Manhattan Project that developed the first atomic weapons. Edward Teller and Ernest Lawrence,[2] director of the Radiation Laboratory at Berkeley, are regarded as the co-founders of the Livermore facility.

    The new laboratory was sited at a former naval air station of World War II. It was already home to several UC Radiation Laboratory projects that were too large for its location in the Berkeley Hills above the UC campus, including one of the first experiments in the magnetic approach to confined thermonuclear reactions (i.e. fusion). About half an hour southeast of Berkeley, the Livermore site provided much greater security for classified projects than an urban university campus.

    Lawrence tapped 32-year-old Herbert York, a former graduate student of his, to run Livermore. Under York, the Lab had four main programs: Project Sherwood (the magnetic-fusion program), Project Whitney (the weapons-design program), diagnostic weapon experiments (both for the Los Alamos and Livermore laboratories), and a basic physics program. York and the new lab embraced the Lawrence “big science” approach, tackling challenging projects with physicists, chemists, engineers, and computational scientists working together in multidisciplinary teams. Lawrence died in August 1958 and shortly after, the university’s board of regents named both laboratories for him, as the Lawrence Radiation Laboratory.

    Historically, the Berkeley and Livermore laboratories have had very close relationships on research projects, business operations, and staff. The Livermore Lab was established initially as a branch of the Berkeley laboratory. The Livermore lab was not officially severed administratively from the Berkeley lab until 1971. To this day, in official planning documents and records, Lawrence Berkeley National Laboratory is designated as Site 100, Lawrence Livermore National Lab as Site 200, and LLNL’s remote test location as Site 300.[3]

    The laboratory was renamed Lawrence Livermore Laboratory (LLL) in 1971. On October 1, 2007 LLNS assumed management of LLNL from the University of California, which had exclusively managed and operated the Laboratory since its inception 55 years before. The laboratory was honored in 2012 by having the synthetic chemical element livermorium named after it. The LLNS takeover of the laboratory has been controversial. In May 2013, an Alameda County jury awarded over $2.7 million to five former laboratory employees who were among 430 employees LLNS laid off during 2008.[4] The jury found that LLNS breached a contractual obligation to terminate the employees only for “reasonable cause.”[5] The five plaintiffs also have pending age discrimination claims against LLNS, which will be heard by a different jury in a separate trial.[6] There are 125 co-plaintiffs awaiting trial on similar claims against LLNS.[7] The May 2008 layoff was the first layoff at the laboratory in nearly 40 years.[6]

    On March 14, 2011, the City of Livermore officially expanded the city’s boundaries to annex LLNL and move it within the city limits. The unanimous vote by the Livermore city council expanded Livermore’s southeastern boundaries to cover 15 land parcels covering 1,057 acres (4.28 km2) that comprise the LLNL site. The site was formerly an unincorporated area of Alameda County. The LLNL campus continues to be owned by the federal government.

    LLNL/NIF


    DOE Seal
    NNSA

     
  • richardmitnick 9:00 am on July 27, 2019 Permalink | Reply
    Tags: "Could this rare supernova resolve a longstanding origin debate?", A major survey of Type Ia supernovae—called 100IAS, Although hydrogen is the most-abundant element in the universe it is almost never seen in Type Ia supernova explosions., ASASSN-18tb is different from these previous events, , , , Carnegie Institution For Science, , Type Ia supernovae originate from the thermonuclear explosion of a white dwarf that is part of a binary system.   

    From Carnegie Institution for Science: “Could this rare supernova resolve a longstanding origin debate?” 

    Carnegie Institution for Science
    From Carnegie Institution for Science

    May 07, 2019

    1
    Cartoon courtesy of Anthony Piro illustrates three possibilities for the origin of the mysterious hydrogen emission from the Type IA supernova called ASASSN-18tb that was observed by Carnegie astronomers.

    2

    Violent Supernova Explosion, ASASSN-18tb, Emitted Large Amounts Of Hydrogen, Scientists Found Out

    Starting from the top and going clockwise: The collision of the explosion with a hydrogen-rich companion star, the explosion triggered by two colliding white dwarf stars subsequently colliding with a third hydrogen-rich star, or the explosion interacting with circumstellar hydrogen material.

    Detection of a supernova with an unusual chemical signature by a team of astronomers led by Carnegie’s Juna Kollmeier—and including Carnegie’s Nidia Morrell, Anthony Piro, Mark Phillips, and Josh Simon—may hold the key to solving the longstanding mystery that is the source of these violent explosions. Observations taken by the Magellan telescopes at Carnegie’s Las Campanas Observatory in Chile [below] were crucial to detecting the emission of hydrogen that makes this supernova, called ASASSN-18tb, so distinctive.

    Their work is published in Monthly Notices of the Royal Astronomical Society.

    Type Ia supernovae play a crucial role in helping astronomers understand the universe. Their brilliance allows them to be seen across great distances and to be used as cosmic mile-markers, which garnered the 2011 Nobel Prize in Physics. Furthermore, their violent explosions synthesize many of the elements that make up the world around us, which are ejected into the galaxy to generate future stars and stellar systems.

    Although hydrogen is the most-abundant element in the universe, it is almost never seen in Type Ia supernova explosions. In fact, the lack of hydrogen is one of the defining features of this category of supernovae and is thought to be a key clue to understanding what came before their explosions. This is why seeing hydrogen emissions coming from this supernova was so surprising.

    Type Ia supernovae originate from the thermonuclear explosion of a white dwarf that is part of a binary system. But what exactly triggers the explosion of the white dwarf—the dead core left after a Sun-like star exhausts its nuclear fuel—is a great puzzle. A prevailing idea is that, the white dwarf gains matter from its companion star, a process that may eventually trigger the explosion, but whether this is the correct theory has been hotly debated for decades.

    This led the research team behind this paper to begin a major survey of Type Ia supernovae—called 100IAS—that was launched when Kollmeier was discussing the origin of these supernovae with study co-authors Subo Dong of Peking University and Doron Kushnir of the Weizmann Institute of Science who, along with Weizmann colleague Boaz Katz, put forward an new theory for Type Ia explosions that involves the violent collision of two white dwarfs.

    Astronomers eagerly study the chemical signatures of the material ejected during these explosions in order to understand the mechanism and players involved in creating Type Ia supernovae.

    In recent years, astronomers have discovered a small number of rare Type Ia supernovae that are cloaked in large amount of hydrogen—maybe as much as the mass of our Sun. But in several respects, ASASSN-18tb is different from these previous events.

    “It’s possible that the hydrogen we see when studying ASASSN-18tb is like these previous supernovae, but there are some striking differences that aren’t so easy to explain,” said Kollmeier.

    First, in all previous cases these hydrogen-cloaked Type Ia supernovae were found in young, star-forming galaxies where plenty of hydrogen-rich gas may be present. But ASASSN-18tb occurred in a galaxy consisting of old stars. Second, the amount of hydrogen ejected by ASASSN-18tb is significantly less than that seen surrounding those other Type Ia supernovae. It probably amounts to about one-hundredth the mass of our Sun.

    “One exciting possibility is that we are seeing material being stripped from the exploding white dwarf’s companion star as the supernova collides with it,” said Anthony Piro. “If this is the case, it would be the first-ever observation of such an occurrence.”

    “I have been looking for this signature for a decade!” said co-author Josh Simon. “We finally found it, but it’s so rare, which is an important piece of the puzzle for solving the mystery of how Type Ia supernovae originate.”

    Nidia Morrell was observing that night, and she immediately reduced the data coming off the telescope and circulated them to the team including Ph.D. student Ping Chen, who works on 100IAS for his thesis and Jose Luis Prieto of Universidad Diego Portales, a veteran supernova observer. Chen was the first to notice that this was not a typical spectrum. All were completely surprised by what they saw in ASASSN-18tb’s spectrum.

    “I was shocked, and I thought to myself ‘could this really be hydrogen?’” recalled Morrell.

    To discuss the observation, Morrell met with team member Mark Phillips, a pioneer in establishing the relationship—informally named after him—that allows Type Ia supernovae to be used as standard rulers. Phillips was convinced: “It is hydrogen you’ve found; no other possible explanation.”

    “This is an unconventional supernova program, but I am an unconventional observer—a theorist, in fact” said Kollmeier. “It’s an extremely painful project for our team to carry out. Observing these things is like catching a knife, because by definition they get fainter and fainter with time! It’s only possible at a place like Carnegie where access to the Magellan telescopes allow us to do time-intensive and sometimes arduous, but extremely important cosmic experiments. No pain, no gain.”

    This research was supported in part by the NSFC.

    See the full article here .


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

    Please help promote STEM in your local schools.

    Stem Education Coalition

    Carnegie Institution of Washington Bldg

    Carnegie Institution for Science

    Andrew Carnegie established a unique organization dedicated to scientific discovery “to encourage, in the broadest and most liberal manner, investigation, research, and discovery and the application of knowledge to the improvement of mankind…” The philosophy was and is to devote the institution’s resources to “exceptional” individuals so that they can explore the most intriguing scientific questions in an atmosphere of complete freedom. Carnegie and his trustees realized that flexibility and freedom were essential to the institution’s success and that tradition is the foundation of the institution today as it supports research in the Earth, space, and life sciences.

    6.5 meter Magellan Telescopes located at Carnegie’s Las Campanas Observatory, Chile.
    6.5 meter Magellan Telescopes located at Carnegie’s Las Campanas Observatory, Chile


    Carnegie Las Campanas 2.5 meter Irénée Dupont telescope, Atacama Desert, over 2,500 m (8,200 ft) high approximately 100 kilometres (62 mi) northeast of the city of La Serena,Chile


    Carnegie Institution Swope telescope at Las Campanas, Chile, 100 kilometres (62 mi) northeast of the city of La Serena. near the north end of a 7 km (4.3 mi) long mountain ridge. Cerro Las Campanas, near the southern end and over 2,500 m (8,200 ft) high, at Las Campanas, Chile

    [/caption]

     
  • richardmitnick 11:36 am on May 4, 2019 Permalink | Reply
    Tags: "When it comes to planetary habitability it’s what’s inside that counts", A true picture of planetary habitability must consider how a planet’s atmosphere is linked to and shaped by what’s happening in its interior, , , , Carnegie Institution For Science, , , , , ,   

    From Carnegie Institution for Science: “When it comes to planetary habitability, it’s what’s inside that counts” 

    Carnegie Institution for Science
    From Carnegie Institution for Science

    May 01, 2019

    Which of Earth’s features were essential for the origin and sustenance of life? And how do scientists identify those features on other worlds?

    A team of Carnegie investigators with array of expertise ranging from geochemistry to planetary science to astronomy published this week in Science an essay urging the research community to recognize the vital importance of a planet’s interior dynamics in creating an environment that’s hospitable for life.

    With our existing capabilities, observing an exoplanet’s atmospheric composition will be the first way to search for signatures of life elsewhere. However, Carnegie’s Anat Shahar, Peter Driscoll, Alycia Weinberger, and George Cody argue that a true picture of planetary habitability must consider how a planet’s atmosphere is linked to and shaped by what’s happening in its interior.

    1
    Reprinted with permission from Shahar et. al., Science Volume 364:3(2019).

    For example, on Earth, plate tectonics are crucial for maintaining a surface climate where life can thrive. What’s more, without the cycling of material between its surface and interior, the convection that drives the Earth’s magnetic field would not be possible and without a magnetic field, we would be bombarded by cosmic radiation.

    “We need a better understanding of how a planet’s composition and interior influence its habitability, starting with Earth,” Shahar said. “This can be used to guide the search for exoplanets and star systems where life could thrive, signatures of which could be detected by telescopes.”

    It all starts with the formation process. Planets are born from the rotating ring of dust and gas that surrounds a young star. The elemental building blocks from which rocky planets form—silicon, magnesium, oxygen, carbon, iron, and hydrogen—are universal. But their abundances and the heating and cooling they experience in their youth will affect their interior chemistry and, in turn, things like ocean volume and atmospheric composition.

    “One of the big questions we need to ask is whether the geologic and dynamic features that make our home planet habitable can be produced on planets with different compositions,” Driscoll explained.

    The Carnegie colleagues assert that the search for extraterrestrial life must be guided by an interdisciplinary approach that combines astronomical observations, laboratory experiments of planetary interior conditions, and mathematical modeling and simulations.

    2
    Artist’s impression of the surface of the planet Barnard’s Star b courtesy of ESO/M. Kornmesser.

    “Carnegie scientists are long-established world leaders in the fields of geochemistry, geophysics, planetary science, astrobiology, and astronomy,” said Weinberger. “So, our institution is perfectly placed to tackle this cross-disciplinary challenge.”

    In the next decade as a new generation of telescopes come online, scientists will begin to search in earnest for biosignatures in the atmospheres of rocky exoplanets. But the colleagues say that these observations must be put in the context of a larger understanding of how a planet’s total makeup and interior geochemistry determines the evolution of a stable and temperate surface where life could perhaps arise and thrive.

    “The heart of habitability is in planetary interiors,” concluded Cody.

    See the full article here .


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

    Please help promote STEM in your local schools.

    Stem Education Coalition

    Carnegie Institution of Washington Bldg

    Carnegie Institution for Science

    Andrew Carnegie established a unique organization dedicated to scientific discovery “to encourage, in the broadest and most liberal manner, investigation, research, and discovery and the application of knowledge to the improvement of mankind…” The philosophy was and is to devote the institution’s resources to “exceptional” individuals so that they can explore the most intriguing scientific questions in an atmosphere of complete freedom. Carnegie and his trustees realized that flexibility and freedom were essential to the institution’s success and that tradition is the foundation of the institution today as it supports research in the Earth, space, and life sciences.

    6.5 meter Magellan Telescopes located at Carnegie’s Las Campanas Observatory, Chile.
    6.5 meter Magellan Telescopes located at Carnegie’s Las Campanas Observatory, Chile


    Carnegie Las Campanas 2.5 meter Irénée Dupont telescope, Atacama Desert, over 2,500 m (8,200 ft) high approximately 100 kilometres (62 mi) northeast of the city of La Serena,Chile


    Carnegie Institution Swope telescope at Las Campanas, Chile, 100 kilometres (62 mi) northeast of the city of La Serena. near the north end of a 7 km (4.3 mi) long mountain ridge. Cerro Las Campanas, near the southern end and over 2,500 m (8,200 ft) high, at Las Campanas, Chile

    [/caption]

     
  • richardmitnick 3:36 pm on April 15, 2019 Permalink | Reply
    Tags: , , , Carnegie Institution For Science, , , The cometary building block material was swallowed by an asteroid and preserved inside this meteorite, The LaPaz meteorite, This research used resources of the Advanced Light Source at LBNL   

    From Carnegie Institution for Science: “Cometary surprise found inside meteorite” 

    Carnegie Institution for Science
    From Carnegie Institution for Science

    April 15, 2019

    An ancient sliver of the building blocks from which comets formed was discovered encased inside a meteorite like an insect in amber by a Carnegie-led research team. The finding, published by Nature Astronomy, could offer clues to the formation and evolution of our Solar System.

    Meteorites were once part of larger bodies, asteroids, which broke up due to collisions in space and survived the trip through the Earth’s atmosphere. Their makeup can vary substantially from meteorite to meteorite, reflecting their varying origin stories in different parent bodies that formed in different parts of the Solar System. Asteroids and comets both formed from the disk of gas and dust that once rotated around our young Sun, but they aggregated at different distances from the Sun, affecting their chemical makeup. Compared to asteroids, comets contain larger fractions of water ice and far more carbon.

    By studying a meteorite’s chemistry and mineralogy, researchers like the paper’s lead author, Carnegie’s Larry Nittler, can reveal details about its formation and how much heating and other chemical processing it experienced during the Solar System’s formative years.

    A particularly primitive class of meteorites called carbonaceous chondrites are thought to have formed beyond Jupiter. One such meteorite, discovered in Antarctica’s LaPaz Icefield, is a particularly pristine example with minimal weathering since its landing on Earth’s surface.

    2
    An illustration showing how a sliver of cometary building block material was swallowed by an asteroid and preserved inside a meteorite, where it was discovered by a Carnegie-led team of scientists. Image is courtesy of Larry Nittler and NASA.

    Inside the LaPaz meteorite, Nittler’s team found a very carbon-rich slice of primitive material that bears some striking similarities to extraterrestrial dust particles that are thought to have originated in comets that formed near the Solar System’s outer edges. Approximately 3-3.5 million years after the Solar System formed, but still long before Earth finished growing, this object—about one tenth of a millimeter across—was captured by the growing asteroid from which the meteorite originated.

    By undertaking sophisticated chemical and isotopic analysis of the material, Nittler and his colleagues—Carnegie’s Conel Alexander and Jemma Davidson (who is now at Arizona State University), as well as Rhonda Stroud and Bradley De Gregorio of the U.S. Naval Research Laboratory, and Josep Trigo-Rodríguez, Carles Moyano-Cambero, and Safoura Tanbakouei of the Institute of Space Sciences in Barcelona, Catalonia—were able to show that the encased material likely originated in the icy outer Solar System along with objects from the Kuiper Belt, where many comets originate.

    Kuiper Belt. Minor Planet Center

    “Because this sample of cometary building block material was swallowed by an asteroid and preserved inside this meteorite, it was protected from the ravages of entering Earth’s atmosphere,” Nittler explained. “It gave us a peek at material that would not have survived to reach our planet’s surface on its own, helping us to understand the early Solar System’s chemistry.”

    The existence of this primitive material inside the meteorite indicates that due to the drag caused by the surrounding gas, particles like it migrated from the outer edges of the Solar System, where comets and Kuiper Belt objects formed, to the closer-in area beyond Jupiter, where the carbonaceous chondrites formed, revealing details about how our Solar System’s architecture was shaped during the early stages of planet formation.

    3
    LaPaz Icefield 02342, named for where it was found in Antarctica, is a primitive meteorite of a type that formed at the dawn of our Solar System’s history. However, the LaPaz meteorite, which is seen here in thin section under polarized light, contains a scientific surprise—a carbon-rich fragment of the building blocks from which comets formed. An arrow points to the cometary fragment. to Image is courtesy of Carles Moyano-Cambero.

    This work was supported by Spanish grants AYA 2011-26522 and AYA 2015-67175-P. and NASA grants NNX10AI63G and NNH16AC42I.

    This research used resources of the Advanced Light Source, which is a DOE Office of Science user Facility at LBNL under contract no. DE-AC02-05CH11231.

    LBNL ALS

    See the full article here .


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

    Please help promote STEM in your local schools.

    Stem Education Coalition

    Carnegie Institution of Washington Bldg

    Carnegie Institution for Science

    Andrew Carnegie established a unique organization dedicated to scientific discovery “to encourage, in the broadest and most liberal manner, investigation, research, and discovery and the application of knowledge to the improvement of mankind…” The philosophy was and is to devote the institution’s resources to “exceptional” individuals so that they can explore the most intriguing scientific questions in an atmosphere of complete freedom. Carnegie and his trustees realized that flexibility and freedom were essential to the institution’s success and that tradition is the foundation of the institution today as it supports research in the Earth, space, and life sciences.

    6.5 meter Magellan Telescopes located at Carnegie’s Las Campanas Observatory, Chile.
    6.5 meter Magellan Telescopes located at Carnegie’s Las Campanas Observatory, Chile


    Carnegie Las Campanas 2.5 meter Irénée Dupont telescope, Atacama Desert, over 2,500 m (8,200 ft) high approximately 100 kilometres (62 mi) northeast of the city of La Serena,Chile


    Carnegie Institution Swope telescope at Las Campanas, Chile, 100 kilometres (62 mi) northeast of the city of La Serena. near the north end of a 7 km (4.3 mi) long mountain ridge. Cerro Las Campanas, near the southern end and over 2,500 m (8,200 ft) high, at Las Campanas, Chile

    [/caption]

     
  • richardmitnick 3:09 pm on April 15, 2019 Permalink | Reply
    Tags: "TESS finds its first Earth-sized planet", , , , Carnegie Institution For Science, , Sibling planet HD 21749c, Sub-Neptune HD 21749b   

    From Carnegie Institution for Science: “TESS finds its first Earth-sized planet” 

    Carnegie Institution for Science
    From Carnegie Institution for Science

    A nearby system hosts the first Earth-sized planet discovered by NASA’s Transiting Exoplanets Survey Satellite, as well as a warm sub-Neptune-sized world, according to a new paper from a team of astronomers that includes Carnegie’s Johanna Teske, Paul Butler, Steve Shectman, Jeff Crane, and Sharon Wang.

    NASA/MIT TESS replaced Kepler in search for exoplanets

    Their work is published in The Astrophysical Journal Letters.

    2
    Artist’s conception of HD 21749c, the first Earth-sized planet found by NASA’s Transiting Exoplanets Survey Satellite (TESS), as well as its sibling, HD 21749b, a warm sub-Neptune-sized world. Illustration by Robin Dienel, courtesy of the Carnegie Institution for Science.

    “It’s so exciting that TESS, which launched just about a year ago, is already a game-changer in the planet-hunting business,” said Teske, who is second author on the paper. “The spacecraft surveys the sky and we collaborate with the TESS follow-up community to flag potentially interesting targets for additional observations using ground-based telescopes and instruments.”

    One such tool, the Planet Finder Spectrograph on the Magellan II telescope at Carnegie’s Las Campanas Observatory in Chile, was a crucial component of this effort. It helped confirm the planetary nature of the TESS signal, and to measure the mass of the newly discovered sub-Neptune.

    Carnegie Planet Finder Spectrograph on the Magellan II Clay telescope

    Carnegie Insitution II Telescope, Clay, in the southern Atacama Desert of Chile 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.

    The PFS—built by Shectman and Crane using a method pioneered by Butler and his collaborators—works using a technique called the radial velocity method, which is currently the only way for astronomers to measure the masses of individual planets.

    Radial velocity Image via SuperWasp http http://www.superwasp.org-exoplanets.htm

    Radial Velocity Method-Las Cumbres Observatory

    Without known masses, it is very challenging to determine a planet’s density or its general chemical composition.

    This method takes advantage of that fact that not only does a star’s gravity influence the planet orbiting it, but the planet’s gravity also affects the star in turn. The PFS enables astronomers to detect these tiny wobbles that the planet’s gravity induces in the star’s orbit.

    “PFS is one of the only instruments in the Southern Hemisphere that can do these types of measurements,” Teske added. “So, it will be a very important part of further characterizing the planets found by the TESS mission.”

    With an orbit that takes about 36 days to complete, the sub-Neptune, HD 21749b, has the longest period of any of the TESS discoveries published so far. Because of the technique that TESS employs, it is predicted that most of the planets the mission finds will have orbital periods of fewer than 10 days, so HD 21749b is unusual in this regard. In fact, this also made the detection of the planet in the TESS data an extra challenge.

    “There was quite some detective work involved, and the right people were there at the right time,” said lead author Diana Dragomir of MIT’s Kavli Institute for Astrophysics and Space Research. “But we were lucky, and we caught the signals, and they were really clear.”

    Its host star has about 80 percent of the mass of our Sun and is found about 53 light-years distant from Earth. HD 21749b has about 23 times Earth’s mass and a radius of about 2.7 times Earth’s. Its density indicates the planet has substantial atmosphere but is not rocky, so it could potentially help astronomers understand the composition and evolution of cooler sub-Neptune planet atmospheres.

    Excitingly, the longer period sub-Neptune planet in this system is not alone. It has a sibling planet, HD 21749c, which takes about eight days to orbit the host star and is much smaller—similar in size to Earth.

    “Measuring the exact mass and composition of such a small planet will be challenging, but important for comparing HD 21749c to Earth,” said Wang. “Carnegie’s PFS team is continuing to collect data on this object with this goal in mind.”

    Thanks to TESS, astronomers will be able to measure the masses, atmospheric compositions, and other properties of many smaller exoplanets for the first time. Although small exoplanets are common in our galaxy, there is still much to learn about their diversity and about how they compare to the planets in our own Solar System.

    “For stars that are very close by and very bright, we expected to find up to a couple dozen Earth-sized planets,” said Dragomir. “And here we are—this would be our first one, and it’s a milestone for TESS. It sets the path for finding smaller planets around even smaller stars, and those planets may potentially be habitable.”

    See the full article here .


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

    Please help promote STEM in your local schools.

    Stem Education Coalition

    Carnegie Institution of Washington Bldg

    Carnegie Institution for Science

    Andrew Carnegie established a unique organization dedicated to scientific discovery “to encourage, in the broadest and most liberal manner, investigation, research, and discovery and the application of knowledge to the improvement of mankind…” The philosophy was and is to devote the institution’s resources to “exceptional” individuals so that they can explore the most intriguing scientific questions in an atmosphere of complete freedom. Carnegie and his trustees realized that flexibility and freedom were essential to the institution’s success and that tradition is the foundation of the institution today as it supports research in the Earth, space, and life sciences.

    6.5 meter Magellan Telescopes located at Carnegie’s Las Campanas Observatory, Chile.
    6.5 meter Magellan Telescopes located at Carnegie’s Las Campanas Observatory, Chile


    Carnegie Las Campanas 2.5 meter Irénée Dupont telescope, Atacama Desert, over 2,500 m (8,200 ft) high approximately 100 kilometres (62 mi) northeast of the city of La Serena,Chile


    Carnegie Institution Swope telescope at Las Campanas, Chile, 100 kilometres (62 mi) northeast of the city of La Serena. near the north end of a 7 km (4.3 mi) long mountain ridge. Cerro Las Campanas, near the southern end and over 2,500 m (8,200 ft) high, at Las Campanas, Chile

    [/caption]

     
  • richardmitnick 1:23 pm on December 18, 2018 Permalink | Reply
    Tags: , , , Carnegie Institution For Science, , Postdoc Spotlight: Eduardo Bañados   

    From Carnegie Institution for Science: “Postdoc Spotlight: Eduardo Bañados” 

    Carnegie Institution for Science
    From Carnegie Institution for Science

    12.17.18

    Postdoc Spotlight: Eduardo Bañados

    1
    We talked to Carnegie-Princeton Fellow Eduardo Bañados before he starts his scientific staff position at the Max Planck Institute for Astronomy in Germany. You’ve no doubt seen his quasar discoveries in the news. Now it’s time to meet the scientist behind the headlines.

    What excites you about your research?

    I like to look into the distant past to understand how we got here. When we look very, very far away, we are looking into a snapshot into the universe’s past. What I am doing is to look as far back as when the first objects in the universe formed, which is a key component to tell us why our universe is the way it is now and what happened in between.

    It’s like astronomical archaeology. Archaeologists dig into the Earth to see the layers and reconstruct the history of our planet. Likewise, in astronomy, we have layers and layers of the universe, and astronomers try to put them together to make sense of it.

    How do you look so far into the early universe?

    It’s difficult! Objects that are far away are also generally very faint. Eventually we’ll have 30-meter class telescopes, like the Giant Magellan Telescope (GMT), which will be better able to observe faint and distant objects.

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

    But I’m impatient. My approach is to use current, large telescopes like the twin Magellans at Las Campanas Observatory to look at extremely bright objects that are also far away.

    Carnegie 6.5 meter Magellan Baade and Clay Telescopes located at Carnegie’s Las Campanas Observatory, Chile. over 2,500 m (8,200 ft) high

    Quasars are the most-luminous objects known, so we can study them even when they are far away. They are supermassive black holes at the center of massive galaxies—a billion times the mass of our Sun—that have material actively falling into it. There is a swirling disk of material around the black hole, which heats up creating an extreme amount of light. Light from a quasar can be a thousand times brighter than the light from the entire galaxy. Not every galaxy has a quasar, so they are exciting when we find them.

    One of the amazing things you’ve done is play a key role in discovering more quasars than has ever been known before, especially very distant quasars. How did you accomplish this?

    When I started at Carnegie three years ago, there were only about 60 very distant quasars known. Today we have about 250 known, most of which I’ve helped discover. The trick is to go farther and deeper with your telescopes, which is a high-risk, high-reward project. Carnegie is one of the few places that gives you access to telescopes and the freedom to try outrageous projects.

    The challenging part in quasar hunting is to identify where we should look. I start by data mining the large astronomical surveys, such as Pan-STARRS, WISE, UKIDSS, and others. I write algorithms to find the needle in a haystack, which is most of my daily work.

    Then we need to confirm that they are indeed distant quasars, and not, say, a nearby brown dwarf. Brown dwarfs and quasars look remarkably similar in some images. Brown dwarfs are intrinsically faint and red, while the quasars I study also look faint and red, but because they are extremely far away. So we use large telescopes to get more data from an individual candidate to characterize better each candidate’s color and other properties. At the end of the day, we take spectra of the most promising candidates and only then we can be sure that what we are looking at is a supermassive black hole accreting material in the center of a galaxy. The spectrum is like a fingerprint that can tell you the chemical composition of an object.

    Your work has made worldwide headlines since starting your fellowship at Carnegie three years ago. Which three discoveries stand out to you?

    First, with my international team of collaborators, we doubled the number of known quasars, tripling those known in the Southern Hemisphere—that was two years ago and this number keeps increasing! Now we can study this population with lots of great telescopes in different wavelengths of light. Having a big atlas of quasars with data allows us to move from studying individual objects to characterizing the whole population. (Read the story here.)

    Second, my colleagues and I started a program using the Atacama Large Millimeter Array, or ALMA, to study the host galaxies where quasars live.

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

    At the long wavelengths that ALMA uses, we can see the galaxies through the dust and gas. The program was a success. We were able to see some of the first massive galaxies that formed in the universe within less than 10 minutes of observation. But an even bigger surprise was that the observations revealed that a quarter of the quasars had another massive galaxy very nearby. Perhaps we are seeing the mechanisms to form these extreme objects or perhaps we are seeing the formation of the first large-scale structures in the universe. This finding was published in the renowned journal Nature. (Read the story here.)

    Third, I found the most-distant quasar ever observed (also published in Nature)—it is from when the universe was only about 5 percent of its current age, and the black hole is about 800 million times the mass of the Sun. I was able to recognize what I had as soon as I saw the spectrum from the Magellan telescope when I was observing. It was really exciting, and an example of that high-risk needle- in-a-haystack search that paid off. (Read the story here.)

    With all of these, there’s so much more work to do and unknown questions to continue to investigate.

    2
    Spectrum of the most-distant quasar ever discovered, courtesy E. Bañados

    What was your path to becoming an astronomer?

    I grew up in Chile, which is home to a huge number of the best telescopes in the world.

    I was always a curious kid and was very interested in science. When I was in high school, my family went on a vacation to La Serena where we went to a tourist telescope in the mountains.

    CTIO Cerro Tololo Inter-American Observatory, CTIO Cerro Tololo Inter-American Observatory,approximately 80 km to the East of La Serena, Chile, at an altitude of 2200 meters

    This was the first time I saw the Milky Way, looked at planets, and realized that you could get paid to look at the stars.

    Then, in my junior year of high school, I took a six-week summer astronomy class at the University of Chile. I got to meet professional astronomers and find out what they do, which made my career path clear.

    I went to Pontificia Universidad Católica de Chile as an undergrad, majoring in astronomy. There, I worked with Leopoldo Infante who is now the director of Carnegie’s Las Campanas Observatory. I received my Ph.D. from the Max Planck Institute for Astronomy (MPIA) in Germany, which is where I’m headed for a scientific staff position in 2019. It’s like there are two circles in my professional career that keep intersecting.

    What has the Carnegie Princeton fellowship meant to you?

    This has been a unique opportunity—Carnegie gives me all the resources that I need to do what I want to do. I get unparalleled access to some of the most powerful telescopes, freedom to pursue my own research, and an amazing group of colleagues who teach me and push me to do new things. For example, I like to call myself a multiwavelength astronomer, but it was at Carnegie where I wrote my first X-ray proposal. It’s great having these experts in-house.

    At Carnegie, I proved that I can lead an international team of astronomers, and at my new position at MPIA I’ll be building a group. Right now, I have more data than I can handle, so my group will help me push the projects forward. And this is just the beginning.

    This is an exciting time to be an astronomer—we’re the first generation who are finding objects at the edge of the universe. I’m really looking forward to using the next generation of telescopes—from space-based missions like the James Webb Space Telescope to the next generation of large ground-based telescopes like the Large Synoptic Survey Telescope and the GMT.

    NASA/ESA/CSA Webb Telescope annotated

    LSST


    LSST Camera, built at SLAC



    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 Gemini South and Southern Astrophysical Research Telescopes.

    All of these will revolutionize our view of the universe, and it is exciting to be part of these projects from the beginning. We’re in a cool epoch of astronomy, but it’s just going to get more interesting.

    See the full article here .


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

    Please help promote STEM in your local schools.

    Stem Education Coalition

    Carnegie Institution of Washington Bldg

    Andrew Carnegie established a unique organization dedicated to scientific discovery “to encourage, in the broadest and most liberal manner, investigation, research, and discovery and the application of knowledge to the improvement of mankind…” The philosophy was and is to devote the institution’s resources to “exceptional” individuals so that they can explore the most intriguing scientific questions in an atmosphere of complete freedom. Carnegie and his trustees realized that flexibility and freedom were essential to the institution’s success and that tradition is the foundation of the institution today as it supports research in the Earth, space, and life sciences.

    6.5 meter Magellan Telescopes located at Carnegie’s Las Campanas Observatory, Chile.
    6.5 meter Magellan Telescopes located at Carnegie’s Las Campanas Observatory, Chile

     
  • richardmitnick 12:55 pm on December 18, 2018 Permalink | Reply
    Tags: , , , , Carnegie Institution For Science, , , Light polution- avoiding it in Chile   

    From Carnegie Institution for Science: “Carnegie astronomers preserve dark skies for generations” 

    Carnegie Institution for Science
    From Carnegie Institution for Science

    1
    Distant lights from Las Campanas Observatory by Ricardo García

    12.16.18
    Guillermo A. Blanc
    Staff Associate Astronomer
    Carnegie Observatories

    Fifty years ago, when the first international observatories were installed in Chile, light pollution seemed unthinkable due to the low population density and small size of villages and mining sites in the Atacama Desert. A few decades later, Chile’s economic growth has brought it to the brink of becoming a developed country. This is great for our operations at Las Campanas Observatory (LCO) because of improved communications, energy, and transportation infrastructure, as well as a better prepared local workforce. But with this development comes the threat of light pollution.

    Carnegie Las Campanas Observatory 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

    Carnegie 6.5 meter Magellan Baade and Clay Telescopes located at Carnegie’s Las Campanas Observatory, Chile. over 2,500 m (8,200 ft) high

    While 50 years ago the main astronomical sites in Chile all had virgin skies, the luminous haloes of growing cities, highways, and mining sites, are starting to have an impact on the sky’s brightness. Currently the Las Campanas sky towards the zenith (that’s looking straight up) is two percent brighter than natural levels. According to simulations based on nighttime satellite imagery, half of this artificial brightness comes from a single source near the observatory: the new lighting system of the Pan-American Highway between La Serena and Vallenar.

    Don’t get me wrong! LCO is still one of the darkest and best sites on the planet for astronomy, but the evolution of light pollution, and the fact that single large projects can have a measurable effect is a bit worrisome and must be addressed. Imagine you are hiking a trail in Yosemite and you find a plastic bag with trash. That doesn’t make Yosemite a polluted park, but a place where action should taken to prevent littering to preserve its beauty. That is exactly what a team of Carnegie astronomers with representatives from other U.S. and European observatories in Chile are doing: raising awareness in the communities and helping the Chilean government in preservation efforts to allow us to have dark skies above the Atacama Desert for generations to come.

    The Carnegie Observatories in a collaboration with the European Southern Observatory (ESO), the Association of Universities for Research in Astronomy (AURA), the Giant Magellan Telescope Organization (GMTO), and the Chilean Government, fund and run the Office for the Protection of the Dark Skies of Chile (OPCC for its acronym in Spanish).

    ESO/Cerro LaSilla, 600 km north of Santiago de Chile at an altitude of 2400 metres.

    ESO VLT at Cerro Paranal in the Atacama Desert, •ANTU (UT1; The Sun ),
    •KUEYEN (UT2; The Moon ),
    •MELIPAL (UT3; The Southern Cross ), and
    •YEPUN (UT4; Venus – as evening star).
    elevation 2,635 m (8,645 ft) from above Credit J.L. Dauvergne & G. Hüdepohl atacama photo

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

    Via the OPCC, we have helped Chile to be in the forefront of light pollution regulation and dark skies preservation. Since 1998, Chile has one of the world’s most stringent regulations controlling outdoor lighting in regions of astronomical interest. In 2014, these regulations were updated to properly address the use of new technologies like LED lighting. The OPCC also runs education and public outreach projects to raise awareness about light pollution and sustainable illumination practices, and organizes scientific workshops bringing together expertise on light pollution across different areas such as astronomy, medicine, biology, energy efficiency, public policy, etc.

    Chilean authorities can advance the protection of these natural laboratories, which are unique in the world. This requires an increase in the levels of compliance with current light pollution regulations and promoting new initiatives, such as the declaration of protected areas in the lands that surround astronomical observatories. It is also essential to establish a requirement to address light pollution in the environmental impact assessments, which are required for the approval of large construction and infrastructure projects like the Pan-American Highway.

    Last October, Carnegie astronomers and our OPCC partners met with the Chilean Minister of the Environment, Carolina Schmidt, in Cerro Paranal. LCO Director, Leopoldo Infante, and myself had the opportunity to talk personally with Minister Schmidt and present the need for Chile to protect the scientific, cultural, and environmental heritage that the dark skies of the Atacama Desert represent. This was just the latest in a series of activities and initiatives involving Carnegie astronomers in Chile, aimed at advocating for the protection of these magical and valuable sites. Protecting the skies above astronomical observatories will ensure that humanity can continue discovering and understanding the universe for generations to come. We were pleased that the minister stated a strong commitment to help us move forward on these issues. In the meantime, we will remain active and vigilant in the protection of our starry nights.

    See the full article here .


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

    Please help promote STEM in your local schools.

    Stem Education Coalition

    Carnegie Institution of Washington Bldg

    Andrew Carnegie established a unique organization dedicated to scientific discovery “to encourage, in the broadest and most liberal manner, investigation, research, and discovery and the application of knowledge to the improvement of mankind…” The philosophy was and is to devote the institution’s resources to “exceptional” individuals so that they can explore the most intriguing scientific questions in an atmosphere of complete freedom. Carnegie and his trustees realized that flexibility and freedom were essential to the institution’s success and that tradition is the foundation of the institution today as it supports research in the Earth, space, and life sciences.

    6.5 meter Magellan Telescopes located at Carnegie’s Las Campanas Observatory, Chile.
    6.5 meter Magellan Telescopes located at Carnegie’s Las Campanas Observatory, Chile

     
  • richardmitnick 5:06 pm on December 17, 2018 Permalink | Reply
    Tags: 2018 VG18-the most-distant body ever observed in our Solar System, , , , Carnegie Institution For Science,   

    “From Carnegie Institution for Science: “Discovered: The Most-Distant Solar System Object Ever Observed” 

    Carnegie Institution for Science
    From Carnegie Institution for Science

    December 17, 2018

    A team of astronomers has discovered the most-distant body ever observed in our Solar System. It is the first known Solar System object that has been detected at a distance that is more than 100 times farther than Earth is from the Sun.

    The new object was announced on Monday, December 17, 2018, by the International Astronomical Union’s Minor Planet Center and has been given the provisional designation 2018 VG18. The discovery was made by Carnegie’s Scott S. Sheppard, the University of Hawaii’s David Tholen, and Northern Arizona University’s Chad Trujillo.

    2018 VG18, nicknamed “Farout” by the discovery team for its extremely distant location, is at about 120 astronomical units (AU), where 1 AU is defined as the distance between the Earth and the Sun. The second-most-distant observed Solar System object is Eris, at about 96 AU. Pluto is currently at about 34 AU, making 2018 VG18 more than three-and-a-half times more distant than the Solar System’s most-famous dwarf planet.

    1
    Solar System distances to scale showing the newly discovered 2018 VG18, nicknamed “Farout,” compared to other known Solar System objects. Illustration by Roberto Molar Candanosa and Scott S. Sheppard is courtesy of the Carnegie Institution for Science.

    2018 VG18 was discovered as part of the team’s continuing search for extremely distant Solar System objects, including the suspected Planet X, which is sometimes also called Planet 9. In October, the same group of researchers announced the discovery of another distant Solar System object, called 2015 TG387 and nicknamed “The Goblin,” because it was first seen near Halloween. The Goblin was discovered at about 80 AU and has an orbit that is consistent with it being influenced by an unseen Super-Earth-sized Planet X on the Solar System’s very distant fringes.

    The existence of a ninth major planet at the fringes of the Solar System was first proposed by this same research team in 2014 when they discovered 2012 VP113, nicknamed Biden, which is currently near 84 AU.

    2015 TG387 and 2012 VP113 never get close enough to the Solar System’s giant planets, like Neptune and Jupiter, to have significant gravitational interactions with them. This means that these extremely distant objects can be probes of what is happening in the Solar System’s outer reaches. The team doesn’t know 2018 VG18’s orbit very well yet, so they have not been able to determine if it shows signs of being shaped by Planet X.

    “2018 VG18 is much more distant and slower moving than any other observed Solar System object, so it will take a few years to fully determine its orbit,” said Sheppard. “But it was found in a similar location on the sky to the other known extreme Solar System objects, suggesting it might have the same type of orbit that most of them do. The orbital similarities shown by many of the known small, distant Solar System bodies was the catalyst for our original assertion that there is a distant, massive planet at several hundred AU shepherding these smaller objects.”

    “All that we currently know about 2018 VG18 is its extreme distance from the Sun, its approximate diameter, and its color,” added Tholen “Because 2018 VG18 is so distant, it orbits very slowly, likely taking more than 1,000 years to take one trip around the Sun.”

    The discovery images of 2018 VG18 were taken at the Japanese Subaru 8-meter telescope located atop Mauna Kea in Hawaii on November 10, 2018.


    NAOJ/Subaru Telescope at Mauna Kea Hawaii, USA,4,207 m (13,802 ft) above sea level

    2
    Discovery images of 2018 VG18, nicknamed “Farout,” from the Subaru Telescope on November 10, 2018. Farout moves between the two discovery images while the background stars and galaxies do not move over the one hour between images. Image is courtesy of Scott S. Sheppard and David Tholen.

    Once 2018 VG18 was found, it needed to be re-observed to confirm its very distant nature. (It takes multiple nights of observing to accurately determine an object’s distance.) 2018 VG18 was seen for the second time in early December at the Magellan telescope at Carnegie’s Las Campanas Observatory in Chile.

    Carnegie 6.5 meter Magellan Baade and Clay Telescopes located at Carnegie’s Las Campanas Observatory, Chile. over 2,500 m (8,200 ft) high

    These recovery observations were performed by the team with the addition of graduate student Will Oldroyd of Northern Arizona University. Over the next week, they monitored 2018 VG18 with the Magellan telescope to secure its path across the sky and obtain its basic physical properties such as brightness and color.

    The Magellan observations confirmed that 2018 VG18 is around 120 AU, making it the first Solar System object observed beyond 100 AU. Its brightness suggests that it is about 500 km in diameter, likely making it spherical in shape and a dwarf planet. It has a pinkish hue, a color generally associated with ice-rich objects.

    “This discovery is truly an international achievement in research using telescopes located in Hawaii and Chile, operated by Japan, as well as by a consortium of research institutions and universities in the United States,” concluded Trujillo. “With new wide-field digital cameras on some of the world’s largest telescopes, we are finally exploring our Solar System’s fringes, far beyond Pluto.”

    The Subaru telescope is owned and operated by Japan and the valuable telescope access that the team obtained was thanks to a combination of time allocated to the University of Hawaii, as well as to the U.S. National Science Foundation (NSF) through telescope time exchanges between the US National Optical Astronomy Observatory (NOAO) and National Astronomical Observatory of Japan (NAOJ).

    See the full article here .


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

    Please help promote STEM in your local schools.

    Stem Education Coalition

    Carnegie Institution of Washington Bldg

    Andrew Carnegie established a unique organization dedicated to scientific discovery “to encourage, in the broadest and most liberal manner, investigation, research, and discovery and the application of knowledge to the improvement of mankind…” The philosophy was and is to devote the institution’s resources to “exceptional” individuals so that they can explore the most intriguing scientific questions in an atmosphere of complete freedom. Carnegie and his trustees realized that flexibility and freedom were essential to the institution’s success and that tradition is the foundation of the institution today as it supports research in the Earth, space, and life sciences.

    6.5 meter Magellan Telescopes located at Carnegie’s Las Campanas Observatory, Chile.
    6.5 meter Magellan Telescopes located at Carnegie’s Las Campanas Observatory, Chile

     
  • richardmitnick 2:20 pm on December 11, 2018 Permalink | Reply
    Tags: , , , Calibrating cosmic mile markers, Carnegie Institution For Science,   

    From Carnegie Institution for Science: “Calibrating cosmic mile markers” 

    Carnegie Institution for Science
    From Carnegie Institution for Science

    December 11, 2018

    New work from the Carnegie Supernova Project provides the best-yet calibrations for using type Ia supernovae to measure cosmic distances, which has implications for our understanding of how fast the universe is expanding and the role dark energy may play in driving this process. Led by Carnegie astronomer Chris Burns, the team’s findings are published in The Astrophysical Journal.

    Type Ia supernovae are fantastically bright stellar phenomena. They are violent explosions of a white dwarf—the crystalline remnant of a star that has exhausted its nuclear fuel—which is part of a binary system with another star.

    1
    An artist’s conception of a type Ia supernova exploding, courtesy of ESO.

    In addition to being exciting to observe in their own right, type Ia supernovae are also a vital tool that astronomers use as a kind of cosmic mile marker to infer the distances of celestial objects.

    While the precise details of the explosion are still unknown, it is believed that they are triggered when the white dwarf approaches a critical mass, so the brightness of the phenomenon is predictable from the energy of the explosion. The difference between the predicted brightness and the brightness observed from Earth tells us the distance to the supernova.

    Astronomers employ these precise distance measurements, along with the speed at which their host galaxies are receding, to determine the rate at which the universe is expanding. Thanks to the finite speed of light, not only can we measure how quickly the universe is expanding right now, but by looking farther and farther out into space, we see further back in time and can measure how fast the universe was expanding in the distant past. This led to the astonishing discovery in the late-1990s that the universe’s expansion is currently speeding up due to the repulsive effect of a mysterious “dark” energy. Improving the distance estimates made using type Ia supernovae will help astronomers better understand the role that dark energy plays in this cosmic expansion.

    “Beginning with its namesake, Edwin Hubble, Carnegie astronomers have a long history of working on the Hubble constant, including vital contributions to our understanding of the universe’s expansion made by Alan Sandage and Wendy Freedman,” said Observatories Director John Mulchaey.

    However, the speed at which the brightness of type Ia supernova explosions fade away is not uniform. In 1993, Carnegie astronomer Mark Phillips showed that the explosions that take longer to fade away are intrinsically brighter than those that fade away quickly. This correlation, which is commonly referred to as the Phillips relation, allowed a group of astronomers in Chile, includingPhillips and Texas A&M astronomer Nicholas Suntzeff, to develop type Ia supernovae into a precise tool for measuring the expansion of the universe.

    Studying the supernovae using the near-infrared part of the spectrum was crucial to this finding. The light from these explosions must travel through cosmic dust to reach our telescopes, and these fine-grained interstellar particles obscure light on the blue end of the spectrum more than they do light from the red end of the spectrum in the same manner as smoke from a forest fire makes everything appear redder. This can trick astronomers into thinking that a supernova is farther away than it is. But working in the infrared allows astronomers to peer more clearly through this dusty veil.

    “One of the Carnegie Supernova Project’s primary goals has been to provide a reliable, high-quality sample of supernovae and dependable methods for inferring their distances,” said lead author Burns.

    “The quality of this data allows us to better correct our measurements to account for the dimming effect of cosmic dust” added Mark Phillips, an astronomer at Carnegie’s Las Campanas Observatory in Chile and a co-author on the paper.

    The calibration of these mile markers is crucially important, because there are disagreements between different methods for determining the universe’s expansion rate. The Hubble constant can independently be estimated using the glow of background radiation left over from the Big Bang. This cosmic microwave background radiation has been measured with exquisite detail by the Planck satellite, and it gives astronomers a more slowly expanding universe than when measured using type Ia supernovae.

    “This discrepancy could herald new physics, but only if it’s real,” Burns explained. “So, we need our type Ia supernova measurements to be as accurate as possible, but also to identify and quantify all sources of error.”

    Other Carnegie co-authors on the paper include: Carlos Contreras, Jorge Anais, Luis Boldt, Luis Busta, Abdo Campillay, Sergio Castellon, Gaston Folatelli, Barry Madore, Consuelo Gonzalez, Wojtek Krzeminski, Nidia Morrell, Eric Persson, Miguel Roth, Francisco Salgado, Jacqueline Serón, and Simon Torres. The other co-authors are: Emilie Parent of McGill University; Maximilian Stritzinger of Arhus University; Kevin Krisciunas and Nicholas B. Suntzeff of Texas A&M University; Wendy Freedman of the University of Chicago; Eric Y. Hsiao and Peter Hoeflich of Florida State University; and Mario Hamuy of Universidad de Chile.

    2
    An artist’s conception of what’s called the cosmic distance ladder—a series of celestial objects, including type Ia supernovae that have known distances and can be used to calculate the rate at which the universe is expanding. Illustration is courtesy of NASA/JPL-Caltech.

    See the full article here .


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

    Please help promote STEM in your local schools.

    Stem Education Coalition

    Carnegie Institution of Washington Bldg

    Andrew Carnegie established a unique organization dedicated to scientific discovery “to encourage, in the broadest and most liberal manner, investigation, research, and discovery and the application of knowledge to the improvement of mankind…” The philosophy was and is to devote the institution’s resources to “exceptional” individuals so that they can explore the most intriguing scientific questions in an atmosphere of complete freedom. Carnegie and his trustees realized that flexibility and freedom were essential to the institution’s success and that tradition is the foundation of the institution today as it supports research in the Earth, space, and life sciences.

    6.5 meter Magellan Telescopes located at Carnegie’s Las Campanas Observatory, Chile.
    6.5 meter Magellan Telescopes located at Carnegie’s Las Campanas Observatory, Chile

     
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