From University of Virginia via phys.org: “Astronomer publishes survey of young stars”

From University of Virginia

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From phys.org

April 5, 2021
Lorenzo Perez, University of Virginia

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An aerial view of the Chajnantor Plateau, located at an altitude of 5,000 meters in the Chilean Andes, where the array of ALMA antennas is located. Credit: Clem & Adri Bacri-Normier (wingsforscience.com)/European Southern Observatory(EU)

An international research group led by a postdoctoral fellow in the University of Virginia’s Department of Astronomy identified a rich organic chemistry in young disks surrounding 50 newly formed stars.

Relying on observations from the Atacama Large Millimeter/submillimeter Array telescope (CL)—known as ALMA—the findings offer astronomers a greater understanding of the mechanisms responsible for the formation of organic molecules in space, at the dawn of planet formation.

The variety of organic molecules identified also raises an important question for astronomers: How common is the chemical heritage of these disks? Since disks around young stars are known to be the sites of future planet formation, understanding their prebiotic potential is key. The findings of the Star and Planet Formation Laboratory of Japan’s RIKEN Cluster for Pioneering Research [開拓研究本部 ](JP) were published March 23 by the American Astronomical Society (US) in The Astrophysical Journal.

“This research is going to help us test our current knowledge about the chemical evolution ongoing in the disks of newly formed stars,” said Yao-Lun Yang, lead author of the paper and an Origins postdoctoral fellow with the Virginia Initiative on Cosmic Origins, based in UVA’s Department of Astronomy. Yang was a Japan Society for the Promotion of Science fellow at RIKEN, a national science research institute in Japan when he began work on the project with other researchers affiliated with RIKEN, the University of Tokyo {東京大学;Tōkyō daigaku](JP), IPAG | Grenoble Institute of Planetology and Astrophysics [Institut de Planétologie et d’Astrophysique de Grenoble] (FR), and other institutions.

“We surveyed the chemical composition of the material where these protoplanetary disks and planets grow from, and what we found quite interesting were the range of complex molecules we observed,” Yang said. “Even where we observed a wide range of total amounts of specific organic molecules, we still found a similar chemical pattern among the different regions we studied.”

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A collection of gas and dust over 500 light-years across, the Perseus Molecular Cloud hosts an abundance of young stars. Credit: National Aeronautics and Space Administration(US)/Jet Propulsion Laboratory-California Institute of Technology(US).

Studying the Perseus Molecular Cloud

Stars form from interstellar clouds, which consist of gas and dust, via gravitational contraction. These young stars are surrounded by disks, which have the potential to evolve into planetary systems. Identifying the initial chemical composition of these forming disks may offer clues to the origins of planets like Earth, Yang said.

The RIKEN-based research focused on 50 sources embedded in the Perseus molecular cloud, which contains young protostars with protoplanetary disks forming around them. Even with the power of the ALMA telescope, it took more than three years, over the course of several projects, to complete the survey. By observing the emission emitted by molecules at specific frequencies, the team studied the amount of methanol, acetonitrile, methyl formate, dimethyl ether, and larger organics—an unprecedented survey of “complex” organic molecules within a large sample of solar-type young stars.

According to the survey, 58% of the sources contained large organic molecules, while 42% of the sources exhibited no sign of them. Surprisingly, the total amount of any given molecule measured showed a wide variety, more than 100 times difference, even for such similar stars. Some sources proved to be rich in organic molecules, even if they had relatively little material surrounding the protostar. Others featured few organic properties, despite a large amount of material surrounding the protostar. Nonetheless, the relative quantities were remarkably similar.

The fact that some systems have substantially more or less total organic content suggests that the evolutionary history of the local environment may have a critical impact to the molecular composition in the resultant planetary systems. While the chemical patterns between systems appear to be relatively similar, some disks may “luck out” with more organic richness compared to others.

Such questions hopefully will be answered in the future through efforts to follow the organic reservoir over time by expanding surveys to even younger or much older systems, Yang said.

See the full article here.

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The University of Virginia is a public research university in Charlottesville, Virginia. It was founded in 1819 by Thomas Jefferson, one of the Founding Fathers of the United States. It is the flagship university of Virginia and home to the Academical Village, a UNESCO World Heritage Site. UVA is known for its historic foundations, student-run honor code and secret societies.

The original governing Board of Visitors included Jefferson, James Madison, and James Monroe. Monroe was the sitting President of the United States at the time of its foundation, and earlier Presidents Jefferson and Madison were UVA’s first two rectors. Jefferson conceived and designed the original courses of study and original architecture. UVA was the first university of the American South elected to the research-driven Association of American Universities (US) in 1904. More than a century later, the journal Science credited UVA faculty with two of the top ten global scientific breakthroughs in a single year (2015).

The University of Virginia offers 121 majors across the eight undergraduate and three professional schools. Its alumni have founded many companies, such as Reddit and CNET, which together produce more than $1.6 trillion in annual revenue and have created 2.3 million jobs. It sits on a historic 1,135-acre (1.8 sq mi; 459.3 ha) central campus partially protected by UNESCO. The university additionally maintains 562 acres north of the campus at North Fork, and 2,913 acres southeast of the city at Morven Farm. Moreover, it manages the College at Wise in Southwest Virginia and until 1972 managed George Mason University and the University of Mary Washington (US) in Northern Virginia.

Virginia student athletes are called Cavaliers and lead the Atlantic Coast Conference in men’s team NCAA Championships with 20, ranking third in women’s and second in overall NCAA titles. Virginia men’s basketball and Virginia men’s lacrosse won NCAA Championships in 2019 to join several Cavalier teams in winning recent national championship events including the College Cup, College World Series, and NCAA Tennis Championships. The collective men’s programs won the Capital One Cup in 2015 and 2019 after leading the nation in overall athletics excellence across all sports. Virginia is one of three universities to win the Cup multiple times.

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The University of Virginia is the first and longest serving member of the Association of American Universities (US) in the American South, attaining membership in 1904. It is classified among “R1: Doctoral Universities – Very high research activity”.

According to the National Science Foundation (US), UVa spent $614 million on research and development in 2019, ranking it 44th in the nation and 1st in Virginia. Built in 1996, North Fork (formerly the UVA Research Park) is an extensive 3.7-million square foot, 562 acre research park nine miles north of UVA’s North Grounds. It houses the UVA Applied Research Institute as well as many private R&D efforts by such firms as Battelle, The MITRE Corporation, Signature Science, and CACI.

UVA is also home to globally recognized research on hypersonic flight for National Aeronautics and Space Administration(US) and others. The United States Air Force, National Science Foundation, and National Center for Hypersonic Combined Cycle Propulsion have each also granted UVA researchers millions in funding for the university’s ongoing broad and deep research into ultra-high velocity flight. Starting in 2015, a UVA team led by mechanical engineering professor Eric Loth began Department of Energy (US) funded research into an original design of offshore wind turbines that would potentially dwarf the size and scope of any being produced or researched anywhere else. The innovative design inspired by palm trees led to Loth being named to a Popular Science list of “The Brilliant Minds Behind The New Energy Revolution”.

UVA was recognized by Science as leading two of the top 10 scientific discoveries in the world in 2015. The first breakthrough was when UVA School of Medicine researchers Jonathan Kipnis and Antoine Louveau discovered previously unknown vessels connecting the human brain directly to the lymphatic system. The discovery “redrew the map” of the lymphatic system, rewrote medical textbooks, and struck down long-held beliefs about how the immune system functions in the brain. The discovery may help greatly in combating neurological diseases from multiple sclerosis to Alzheimer’s disease. The second globally recognized breakthrough of 2015 was when UVA psychology professor Brian Nosek examined the reproducibility of 100 psychology studies and found fewer than half could be reproduced. The discovery may have profound impacts on how psychological studies are performed and documented. More than 270 researchers on five continents were involved, and twenty-two students and faculty from UVA were listed as co-authors on the scientific paper.

In the field of astrophysics, the university is a member of a consortium engaged in the construction and operation of the Large Binocular Telescope in the U Arizona Mount Graham International Observatory (US) of the Pinaleno Mountains of southeastern Arizona. It is also a member of both the Astrophysical Research Consortium (US), which operates telescopes at Apache Point Observatory (US) in New Mexico, and the Association of Universities for Research in Astronomy (US) which operates the National Optical Astronomy Observatory (US), the NOIRLab NOAO Gemini Observatory (US) and the National Aeronautics and Space Administration(US) Space Telescope Science Institute (US). The University of Virginia hosts the headquarters of the National Radio Astronomy Observatory (US), which operates the Green Bank Telescope (US) in West Virginia and the National Science Foundation(US) National Radio Astronomy Observatory(US) Very Large Array radio telescope made famous in the Carl Sagan television documentary Cosmos and film Contact. The North American Atacama Large Millimeter Array Science Center is also at the Charlottesville NRAO site. In 2019, researchers at NRAO co-authored a study documenting the discovery of a pair of giant hourglass shaped balloons emanating radio waves from the center of our Milky Way galaxy.