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  • 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

     
  • richardmitnick 3:13 pm on November 30, 2018 Permalink | Reply
    Tags: ASASSN18bt Type 1a supernova, , , , Carnegie Institution For Science, , Newly discovered supernova complicates origin story theories, Ohio State world wide All-Sky Automated Survey for Supernovae (ASAS-SN), Type 1a supernova   

    From Carnegie Institution for Science: “Newly discovered supernova complicates origin story theories” 

    Carnegie Institution for Science
    From Carnegie Institution for Science

    November 29, 2018
    Anthony Piro

    A supernova discovered by an international group of astronomers including Carnegie’s Tom Holoien and Maria Drout, and led by University of Hawaii’s Ben Shappee, provides an unprecedented look at the first moments of a violent stellar explosion. The light from the explosion’s first hours showed an unexpected pattern, which Carnegie’s Anthony Piro analyzed to reveal that the genesis of these phenomena is even more mysterious than previously thought.

    Their findings are published in a trio of papers in The Astrophysical Journal and The Astrophysical Journal Letters. (You can read them here, here, and here.)

    2

    Type Ia supernovae are fundamental to our understanding of the cosmos. Their nuclear furnaces are crucial for generating many of the elements around us, and they are used as cosmic rulers to measure distances across the universe. Despite their importance, the actual mechanism that triggers a Type Ia supernova explosion has remained elusive for decades.

    That’s why catching them in the act is crucial.

    Astronomers have long tried to get detailed data at the initial moments of these explosions, with the hope of figuring out how these phenomena are triggered. This finally happened in February of this year with the discovery of a Type Ia supernova called ASASSN-18bt (also known as SN 2018oh).

    ASASSN-18bt was discovered by the All-Sky Automated Survey for Supernovae (ASAS-SN), an international network of telescopes headquartered at the Ohio State University that routinely scans the sky for supernovae and other cosmic explosions.

    ASAS-SN’s hardware. Off the shelf Mark Elphick-Los Cumbres Observatory

    NASA’s Kepler space telescope was simultaneously able to take complementary data of this event. Kepler was designed to be incredibly sensitive to small changes in light for its mission of detecting extrasolar planets, so it was able to obtain especially detailed information about the explosion’s genesis.

    NASA/Kepler Telescope

    “ASASSN-18bt is the nearest and brightest supernova yet observed by Kepler, so it offered an excellent opportunity to test the predominant theories of supernova formation,” said Shappee, who is lead author on the on the discovery and early time light curve paperand one of our Carnegie alumni.

    Combining data from ASAS-SN, Kepler, and telescopes around the world, the astronomers realized that ASASSN-18bt looked unusual during its first couple of days.

    “Many supernovae show a gradual increase in the light they put out,” said Drout, who is jointly appointed at the University of Toronto. “But for this event, you could clearly see there’s something unusual and exciting happening in the early times—an unexpected additional emission.”

    Type Ia supernovae originate from the thermonuclear explosion of a white dwarf star—the dead core left over by a Sun-like star after it exhausts its nuclear fuel. Material must be added to the white dwarf from a companion star to trigger the explosion, but the nature of the companion star and how the fuel is transferred has long been debated.

    One possibility is that this additional light seen during the supernova’s early times could be from the exploding white dwarf colliding with the companion star. Although this was the initial hypothesis, detailed comparisons with Piro’s theoretical modeling work demonstrated that this additional light may have a different, unexplained origin.

    “While the steep increase in ASASSN-18bt’s early brightness could indicate that the explosion collides with another star, our follow-up data don’t fit predictions for how this should look,” Holoien said. “Other possibilities, such as an unusual distribution of radioactive material in the exploded star, are a better explanation for what we saw. More observations of ASASSN-18bt and more early discoveries like this one will hopefully help us differentiate between different models and better understand the origins of these explosions.”

    “Nature is always finding new ways to surprise us, and unique observations like this are great for motivating creative new approaches to how we think about these explosions,” added Piro. “As a theorist at the Carnegie Observatories, it’s so helpful and inspiring to be right near the observers who are making these key measurements.”

    This supports a hypothesis put forward in recent work from the Carnegie Supernova Project, led by Maximilian Stritzinger ofAarhus University and co-led by Shappee and Piro, that there may be two distinct populations of Type Ia supernovae—those that show early emission and those that do not.

    Thanks to ASAS-SN and the next generation of surveys that are now monitoring the sky every night, astronomers will find even more new supernovae and catch them at the moment of explosion.

    4
    Six images showing the host galaxy of the newly discovered supernova ASASSN-18bt. The top row shows three images from before the explosion taken by Pan-STARRS, ASAS-SN, and Kepler. The bottom row shows images from ASAS-SN and Kepler after the supernova was visible. The discovery image from the ASAS-SN team is in the bottom middle. To its left is a version with all the surrounding stars eliminated, showing only the new supernova’s light output. On the bottom right is a Kepler image from after the supernova was detected. Kepler’s precision was crucial to understanding the light from ASASSN_18bt in the early hours after the explosion.

    Combining data from ASAS-SN, Kepler, Pan-STARRS, ATLAS, and telescopes from around the world, the astronomers realized that ASASSN-18bt looked unusual during its first couple of days. “Many supernovae show a gradual increase in the light they put out,” said Maria Drout, assistant professor at the University of Toronto and third author on the discovery paper. “But for this event, you could clearly see something unusual and exciting happening in the early times—some unexpected additional emission.”

    As more of these events are found and studied, they will hopefully home in on the solution to the longstanding mystery of how these stellar explosions originate.

    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 2:26 pm on October 11, 2018 Permalink | Reply
    Tags: , , , , , Carnegie Institution For Science, , iPTF=intermediate Palomar Transient Factory, Massive star’s unusual death heralds the birth of compact neutron star binary,   

    From Carnegie Institution for Science: “Massive star’s unusual death heralds the birth of compact neutron star binary” 

    Carnegie Institution for Science
    From Carnegie Institution for Science

    October 11, 2018

    1

    Carnegie’s Anthony Piro was part of a Caltech-led team of astronomers who observed the peculiar death of a massive star that exploded in a surprisingly faint and rapidly fading supernova, possibly creating a compact neutron star binary system. Piro’s theoretical work provided crucial context for the discovery. Their findings are published by Science.

    Observations made by the Caltech team—including lead author Kishalay De and project principal investigator Mansi Kasliwal (herself a former-Carnegie postdoc)—suggest that the dying star had an unseen companion, which gravitationally siphoned away most of the star’s mass before it exploded as a supernova. The explosion is believed to have resulted in a neutron star binary, suggesting that, for the first time, scientists have witnessed the birth of a binary system like the one first observed to collide by Piro and a team of Carnegie and UC Santa Cruz astronomers in August 2017.

    A supernova occurs when a massive star—at least eight times the mass of the Sun—exhausts its nuclear fuel, causing the core to collapse and then rebound outward in a powerful explosion. After the star’s outer layers have been blasted away, all that remains is a dense neutron star—an exotic star about the size of a city but containing more mass than the Sun.

    Usually, a lot of material—many times the mass of the Sun—is observed to be blasted away in a supernova. However, the event that Kasliwal and her colleagues observed, dubbed iPTF 14gqr, ejected matter only one fifth of the Sun’s mass.

    “We saw this massive star’s core collapse, but we saw remarkably little mass ejected,” Kasliwal says. “We call this an ultra-stripped envelope supernova and it has long been predicted that they exist. This is the first time we have convincingly seen core collapse of a massive star that is so devoid of matter.”

    Piro’s theoretical modeling guided the interpretation of these observations. This allowed the observers to infer the presence of dense material surrounding the explosion.

    “Discoveries like this demonstrate why it has been so important to build a theoretical astrophysics group at Carnegie,” Piro said. “By combining observations and theory together, we can learn so much more about these amazing events.”

    The fact that the star exploded at all implies that it must have previously had a lot of material, or its core would never have grown large enough to collapse. But where was the missing mass hiding? The researchers inferred that the mass must have been stolen by a compact companion star, such as a white dwarf, neutron star, or black hole.

    The neutron star that was left behind from the supernova must have then been born into orbit with this compact companion. Because this new neutron star and its companion are so close together, they will eventually merge in a collision. In fact, the merger of two neutron stars was first observed in August 2017 by Piro and a team of Carnegie and UC Santa Cruz astronomers, and such events are thought to produce the heavy elements in our universe, such as gold, platinum, and uranium.

    The event was first seen at Palomar Observatory as part of the intermediate Palomar Transient Factory (iPTF), a nightly survey of the sky to look for transient, or short-lived, cosmic events like supernovae.

    Caltech Palomar Observatory, located in San Diego County, California, US, at 1,712 m (5,617 ft)

    Caltech Palomar Intermediate Palomar Transient Factory telescope at the Samuel Oschin Telescope at Palomar Observatory,located in San Diego County, California, United States

    Because the iPTF survey keeps such a close eye on the sky, iPTF 14gqr was observed in the very first hours after it had exploded. As the earth rotated and the Palomar telescope moved out of range, astronomers around the world collaborated to monitor iPTF 14gqr, continuously observing its evolution with a number of telescopes that today form the Global Relay of Observatories Watching Transients Happen (GROWTH) network of observatories.

    GROWTH map

    3
    The three panels represent moments before, when and after the faint supernova iPTF14gqr, visible in the middle panel, appeared in the outskirts of a spiral galaxy located 920 million light years away from us. The massive star that died in the supernova left behind a neutron star in a very tight binary system. These dense stellar remnants will ultimately spiral into each other and merge in a spectacular explosion, giving off gravitational and electromagnetic waves. Image credit: SDSS/Caltech/Keck

    SDSS Telescope at Apache Point Observatory, near Sunspot NM, USA, Altitude 2,788 meters (9,147 ft)


    Keck Observatory, Maunakea, Hawaii, USA.4,207 m (13,802 ft), above sea level, showing also NASA’s IRTF and NAOJ Subaru

    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 2:25 pm on October 2, 2018 Permalink | Reply
    Tags: , , , Carnegie Institution For Science, , early galaxy formation, Newly discovered quasar called PSO J352.4034–15.3373, Plasma-spewing quasar shines light on universe’s youth   

    From Carnegie Institution for Science: “Plasma-spewing quasar shines light on universe’s youth, early galaxy formation” 

    Carnegie Institution for Science
    From Carnegie Institution for Science

    July 09, 2018 [Just now in social media]
    No writer credit

    1
    An artist’s conception of a radio jet spewing out fast-moving material from the newly discovered quasar. Artwork by Robin Dienel, courtesy of Carnegie Institution for Science.

    Carnegie’s Eduardo Bañados led a team that found a quasar with the brightest radio emission ever observed in the early universe, due to it spewing out a jet of extremely fast-moving material.

    Bañados’ discovery was followed up by Emmanuel Momjian of the National Radio Astronomy Observatory, which allowed the team to see with unprecedented detail the jet shooting out of a quasar that formed within the universe’s first billion years of existence.

    The findings, published in two [?] papers in The Astrophysical Journal, will allow astronomers to better probe the universe’s youth during an important period of transition to its current state.

    Quasars are comprised of enormous black holes accreting matter at the centers of massive galaxies. This newly discovered quasar, called PSO J352.4034–15.3373, is one of a rare breed that doesn’t just swallow matter into the black hole but also emits a jet of plasma traveling at speeds approaching that of light. This jet makes it extremely bright in the frequencies detected by radio telescopes. Although quasars were identified more than 50 years ago by their strong radio emissions, now we know that only about 10 percent of them are strong radio emitters.

    What’s more, this newly discovered quasar’s light has been traveling nearly 13 billion of the universe’s 13.7 billion years to reach us here in Earth. P352-15 is the first quasar with clear evidence of radio jets seen within the first billion years of the universe’s history.

    “There is a dearth of known strong radio emitters from the universe’s youth and this is the brightest radio quasar at that epoch by an order of magnitude,” Bañados said.

    “This is the most-detailed image yet of such a bright galaxy at this great distance,” Momjian added.

    The Big Bang started the universe as a hot soup of extremely energetic particles that were rapidly expanding. As it expanded, it cooled and coalesced into neutral hydrogen gas, which left the universe dark, without any luminous sources, until gravity condensed matter into the first stars and galaxies. About 800 million years after the Big Bang, the energy released by these first galaxies caused the neutral hydrogen that was scattered throughout the universe to get excited and lose an electron, or ionize, a state that the gas has remained in since that time.

    It’s highly unusual to find radio jet-emitting quasars such as this one from the period just after the universe’s lights came back on.

    “The jet from this quasar could serve as an important calibration tool to help future projects penetrate the dark ages and perhaps reveal how the earliest galaxies came into being,” Bañados concluded.

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

    This paper includes data gathered with Carnegie’s 6.5-meter Magellan Telescopes located at 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

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

    Pann-STARSR1 Telescope, U Hawaii, Mauna Kea, Hawaii, USA, Altitude 3,052 m (10,013 ft)

    The Pan-STARRS1 Surveys (PS1) and the PS1 public science archive have been made possible through contributions by the Institute for Astronomy, the University of Hawaii, the Pan-STARRS Project Office, the Max-Planck Society and its participating institutes, the Max Planck Institute for Astronomy, Heidelberg and the Max Planck Institute for Extraterrestrial Physics, Garching, The Johns Hopkins University, Durham University, the University of Edinburgh, the Queen’s University Belfast, the Harvard-Smithsonian Center for Astrophysics, the Las Cumbres Observatory Global Telescope Network Incorporated, the National Central University of Taiwan, the Space Telescope Science Institute, NAS, the National Science Foundation, the University of Maryland, Eotvos Lorand Universiy, the Los Alamos National Laboratory, and the Gordon and Betty Moore Foundation.

    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 8:13 am on August 17, 2018 Permalink | Reply
    Tags: , , , Carnegie Institution For Science, , hydrogen offers a reflection of giant planet interiors, , Under pressure   

    From Carnegie Institution for Science: “Under pressure, hydrogen offers a reflection of giant planet interiors” 

    Carnegie Institution for Science
    From Carnegie Institution for Science

    1
    Unraveling the properties of fluid metallic hydrogen at the National Ignition Facility could help scientists unlock the mysteries of Jupiter’s formation and internal structure. Credit: Mark Meamber, LLNL.

    National Ignition Facility at LLNL

    August 15, 2018

    Lab-based mimicry allowed an international team of physicists including Carnegie’s Alexander Goncharov to probe hydrogen under the conditions found in the interiors of giant planets—where experts believe it gets squeezed until it becomes a liquid metal, capable of conducting electricity. Their work is published in Science.

    Hydrogen is the most-abundant element in the universe and the simplest—comprised of only a one proton and one electron in each atom. But that simplicity is deceptive, because there is still so much to learn about it, including its behavior under conditions not found on Earth.

    For example, although hydrogen on the surface of giant planets, like our Solar System’s Jupiter and Saturn, is a gas, just like it is on our own planet, deep inside these giant planetary interiors, scientists believe it becomes a metallic liquid.

    “This transformation has been a longstanding focus of attention in physics and planetary science,” said lead author Peter Celliers of Lawrence Livermore National Laboratory.

    The research team—which also included scientists from the French Alternative Energies and Atomic Energy Commission, University of Edinburgh, University of Rochester, University of California Berkeley, and George Washington University—focused on this gas-to-metallic-liquid transition in molecular hydrogen’s heavier isotope deuterium. (Isotopes are atoms of the same element that have the same number of protons but a different number of neutrons.)

    They studied how deuterium’s ability to absorb or reflect light changed under up to nearly six million times normal atmospheric pressure (600 gigapascals) and at temperatures less than 1,700 degrees Celsius (about 3,140 degrees Fahrenheit). Reflectivity can indicate that a material is metallic.

    2
    A dynamic storm at the southern edge of Jupiter’s northern polar region dominates this Jovian cloudscape, courtesy of NASA’s Juno spacecraft. Image credits: NASA/JPL Caltech/SwRI/MSSS/Gerald Eichstädt/Seán Doran

    NASA/Juno

    They found that under about 1.5 million times normal atmospheric pressure (150 gigapascals) the deuterium switched from transparent to opaque—absorbing the light instead of allowing it to pass through. But a transition to metal-like reflectivity started at nearly 2 million times normal atmospheric pressure (200 gigapascals).

    “To build better models of potential exoplanetary architecture, this transition between gas and metallic liquid hydrogen must be demonstrated and understood,” Goncharov explained. “Which is why we focused on pinpointing the onset of reflectivity in compressed deuterium, moving us closer to a complete vision of this important process.”

    The research team included: Marius Millot, Dayne Fratanduono, Jon Eggert, J. Luc Peterson, Nathan Meezan, and Sebastien Le Pape of Lawrence Livermore National Laboratories; Stephanie Brygoo and Paul Loubeyre of the French Alternative Energies and Atomic Energy Commission’s Division of Military Applications; R. Stewart McWilliams of University of Edinburgh; J. Ryan Rygg and Gilbert Collins of University of Rochester (both also of LLNL); Raymond Jeanloz of University of California Berkeley; and Russell Hemley of George Washington University.

    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 9:19 am on August 7, 2018 Permalink | Reply
    Tags: , Carnegie Institution For Science, , , Pacific Ocean’s Effect on Arctic Warming   

    From Carnegie Institution for Science: “Pacific Ocean’s Effect on Arctic Warming” 

    Carnegie Institution for Science
    From Carnegie Institution for Science

    August 07, 2018

    1
    This image was taken in September 2016 showing the extent of Arctic sea ice then. The yellow line shows the average minimum extent of sea ice in the Arctic from 1981 to 2010. Image courtesy NASA

    New research, led by former Carnegie postdoctoral fellow Summer Praetorius, shows that changes in the heat flow of the northern Pacific Ocean may have a larger effect on the Arctic climate than previously thought. The findings are published in the August 7, 2018, issue of Nature Communications.

    The Arctic is experiencing larger and more rapid increases in temperature from global warming more than any other region, with sea-ice declining faster than predicted. This effect, known as Arctic amplification, is a well-established response that involves many positive feedback mechanisms in polar regions.

    What has not been well understood is how sea-surface temperature patterns and oceanic heat flow from Earth’s different regions, including the temperate latitudes, affect these polar feedbacks. This new research suggests that the importance of changes occurring in the Pacific may have a stronger impact on Arctic climate than previously recognized.

    Paleoclimate records show that climate change in the Arctic can be very large and happen very rapidly. During the last deglaciation, as the planet was starting to warm from rising greenhouse gases, there were two episodes of accelerated warming in the Arctic—with temperatures increasing by 15°C (27°F) in Greenland over the course of decades. Both events were accompanied by rapid warming in the mid-latitude North Pacific and North Atlantic oceans.

    Using these past changes as motivation for the current study, the research team* modeled a series of ocean-to-atmosphere heat flow scenarios for the North Pacific and the North Atlantic. They used the National Center for Atmospheric Research’s Community Earth System Model (CESM), to assess the impacts to the Arctic’s surface temperature and climate feedbacks.

    Praetorius, who was at Carnegie at the time of the research and is now with the USGS in Menlo Park, CA explained: “Since there appeared to be coupling between abrupt Arctic temperature changes and sea surface temperature changes in both the North Atlantic and North Pacific in the past, we thought it was important to untangle how each region may affect the Arctic differently in order to provide insight into recent and future Arctic changes.”

    The researchers found that both cooling and warming anomalies in the North Pacific resulted in greater global and Arctic surface air temperature anomalies than the same perturbations modeled for the North Atlantic. Until now, this sensitivity had been underappreciated.

    The scientists looked at several mechanisms that could be causing the changes and found that the strong global and Arctic changes depended on the magnitude of water vapor transfer from the mid-latitude oceans to the Arctic. When warm moist air is carried poleward towards the Arctic, it can lead to more low-lying clouds that act like a blanket, trapping warmth near the surface. The poleward movement of heat and moisture drive the Arctic’s sea-ice retreat and low-cloud formation, amplifying Arctic warming.

    The so-called ice-albedo feedback causes retreating ice and snow to lead to ever greater warming through increasing absorption of solar energy on darker surfaces.

    In very recent years, the Arctic has experienced an even greater acceleration in warming. The authors note that the unusually warm ocean temperatures in the Northeast Pacific paralleled the uptick in Arctic warming, possibly signaling a stronger link between these regions than generally recognized.

    “While this is a highly idealized study, our results suggest that changes in the Pacific Ocean may have a larger influence on the climate system than generally recognized,” remarked Carnegie coauthor Ken Caldeira.

    • Co-authors are Summer Praetorius, USGS, Menlo Park, CA; Maria Rugenstein, Institute for Atmospheric and Climate Science, Zurich; and Geeta Persad and Ken Caldeira of Carnegie’s Department of Global Ecology, Stanford, CA.

    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 12:45 pm on July 17, 2018 Permalink | Reply
    Tags: , , , Carnegie Institution For Science, , Twelve new Jovian moons   

    From Carnegie Institution for Science: “A dozen new moons of Jupiter discovered, including one ‘oddball'” 

    Carnegie Institution for Science
    From Carnegie Institution for Science

    July 16, 2018

    Twelve new moons orbiting Jupiter have been found—11 “normal” outer moons, and one that they’re calling an “oddball.” This brings Jupiter’s total number of known moons to a whopping 79—the most of any planet in our Solar System.

    A team led by Carnegie’s Scott S. Sheppard first spotted the moons in the spring of 2017 while they were looking for very distant Solar System objects as part of the hunt for a possible massive planet far beyond Pluto.

    In 2014, this same team found the object with the most-distant known orbit in our Solar System and was the first to realize that an unknown massive planet at the fringes of our Solar System, far beyond Pluto, could explain the similarity of the orbits of several small extremely distant objects. This putative planet is now sometimes popularly called Planet X or Planet Nine. University of Hawaii’s Dave Tholen and Northern Arizona University’s Chad Trujillo are also part of the planet search team.

    “Jupiter just happened to be in the sky near the search fields where we were looking for extremely distant Solar System objects, so we were serendipitously able to look for new moons around Jupiter while at the same time looking for planets at the fringes of our Solar System,” said Sheppard.

    Gareth Williams at the International Astronomical Union’s Minor Planet Center used the team’s observations to calculate orbits for the newly found moons.

    “It takes several observations to confirm an object actually orbits around Jupiter,” Williams said. “So, the whole process took a year.”

    Nine of the new moons are part of a distant outer swarm of moons that orbit it in the retrograde, or opposite direction of Jupiter’s spin rotation. These distant retrograde moons are grouped into at least three distinct orbital groupings and are thought to be the remnants of three once-larger parent bodies that broke apart during collisions with asteroids, comets, or other moons. The newly discovered retrograde moons take about two years to orbit Jupiter.

    Two of the new discoveries are part of a closer, inner group of moons that orbit in the prograde, or same direction as the planet’s rotation. These inner prograde moons all have similar orbital distances and angles of inclinations around Jupiter and so are thought to also be fragments of a larger moon that was broken apart. These two newly discovered moons take a little less than a year to travel around Jupiter.

    “Our other discovery is a real oddball and has an orbit like no other known Jovian moon,” Sheppard explained. “It’s also likely Jupiter’s smallest known moon, being less than one kilometer in diameter”.

    This new “oddball” moon is more distant and more inclined than the prograde group of moons and takes about one and a half years to orbit Jupiter. So, unlike the closer-in prograde group of moons, this new oddball prograde moon has an orbit that crosses the outer retrograde moons.

    As a result, head-on collisions are much more likely to occur between the “oddball” prograde and the retrograde moons, which are moving in opposite directions.

    “This is an unstable situation,” said Sheppard. “Head-on collisions would quickly break apart and grind the objects down to dust.”

    It’s possible the various orbital moon groupings we see today were formed in the distant past through this exact mechanism.

    The team think this small “oddball” prograde moon could be the last-remaining remnant of a once-larger prograde-orbiting moon that formed some of the retrograde moon groupings during past head-on collisions. The name Valetudo has been proposed for it, after the Roman god Jupiter’s great-granddaughter, the goddess of health and hygiene.

    Elucidating the complex influences that shaped a moon’s orbital history can teach scientists about our Solar System’s early years.

    For example, the discovery that the smallest moons in Jupiter’s various orbital groups are still abundant suggests the collisions that created them occurred after the era of planet formation, when the Sun was still surrounded by a rotating disk of gas and dust from which the planets were born.

    Because of their sizes—one to three kilometers—these moons are more influenced by surrounding gas and dust. If these raw materials had still been present when Jupiter’s first generation of moons collided to form its current clustered groupings of moons, the drag exerted by any remaining gas and dust on the smaller moons would have been sufficient to cause them to spiral inwards toward Jupiter. Their existence shows that they were likely formed after this gas and dust dissipated.

    3
    Recovery images of Valetudo from the Magellan telescope in May 2018. The moon can be seen moving relative to the steady state background of distant stars. Jupiter is not in the field but off to the upper left.

    The initial discovery of most of the new moons were made on the Blanco 4-meter telescope at Cerro Tololo Inter-American in Chile and operated by the National Optical Astronomical Observatory of the United States. The telescope recently was upgraded with the Dark Energy Camera, making it a powerful tool for surveying the night sky for faint objects.

    Dark Energy Survey


    Dark Energy Camera [DECam], built at FNAL


    NOAO/CTIO Victor M Blanco 4m Telescope which houses the DECam at Cerro Tololo, Chile, housing DECam at an altitude of 7200 feet

    Several telescopes were used to confirm the finds, including the 6.5-meter Magellan telescope at Carnegie’s Las Campanas Observatory in Chile; the 4-meter Discovery Channel Telescope at Lowell Observatory Arizona (thanks to Audrey Thirouin, Nick Moskovitz and Maxime Devogele); the 8-meter Subaru Telescope and the University of Hawaii 2.2 meter telescope (thanks to Dave Tholen and Dora Fohring at the University of Hawaii); and 8-meter Gemini Telescope in Hawaii (thanks to Director’s Discretionary Time to recover Valetudo). Bob Jacobson and Marina Brozovic at NASA’s Jet Propulsion Laboratory confirmed the calculated orbit of the unusual oddball moon in 2017 in order to double check its location prediction during the 2018 recovery observations in order to make sure the new interesting moon was not lost.

    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

    Discovery Channel Telescope at Lowell Observatory, Happy Jack AZ, USA, Altitude 2,360 m (7,740 ft)


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


    U Hawaii 2.2 meter telescope, Mauna Kea, Hawaii, USA,4,207 m (13,802 ft) above sea level


    Gemini/North telescope at Maunakea, Hawaii, USA,4,207 m (13,802 ft) above sea level

    5

    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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