Jesse Lieman-Sifry ’15 visited the Sub Millimeter Array in Hawaii this summer to help observe, learn about how radio astronomy data is collected, and see the array of antennas up close. Lieman-Sifry recently received a $5,000 Undergraduate Directed Campus Scholarship from the Connecticut Space Grant Consortium to support his ongoing research on gas planet formation.
For the past year and a half, Jesse Lieman-Sifry ’15, an astronomy and physics double major, has focused his undergraduate research on understanding the formation of gas planets. This month, Lieman-Sifry received a $5,000 Undergraduate Directed Campus Scholarship from the Connecticut Space Grant Consortium, funded by NASA. The award will be applied to his financial aid package and support his ongoing research in the Astronomy Department.
Jesse Lieman-Sifry uses data to model the dust and gas on a specific star system called 49 Ceti. 49 Ceti is visible to the naked eye.
Planets form in disks of gas and dust left over from the formation of a star. For gas planets, such as Jupiter, Saturn, Uranus and Neptune, a massive rocky core must solidify before accumulation of gas can begin.
“In the 10 million years we assume it takes this rocky core to form, most of the gas has been blown away by the energy from the hot central star. This would suggest that it is very hard to form gas planets, as the timeline for these processes don’t line up,” Lieman-Sifry explained. “Something about this picture isn’t quite right though, as the planet-hunting Kepler mission has revealed that gas planets are actually very common around other stars in the Milky Way.”
Lieman-Sifry is working with high-resolution data collected by the Atacama Large Millimeter Array (ALMA) in Chile. The data, provided from radio interferometers,
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Assistant professor of Astronomy Meredith Hughes and eight colleagues have found evidence of magnetic fields in stardust – an indication that magnetic fields are important in the process of planetary system formation, according to a new paper in the journal Nature.
The discovery is another step in work by Hughes and other astronomers to understand how celestial bodies are formed. It is known that magnetic fields in the “accretion disks” of stars play a dominant role in the star formation process.
Using data from an observatory near Bishop, Calf., Hughes and her colleagues were able to spot signs of magnetic fields in the dust of the disk of a star about 300 light years away. While magnetic fields have been detected in regions that represent the very earliest stages of star formation (the so-called Class 0 and Class I stages), this is the first time they have been seen around a star with an older age closer to when we believe planetary systems form.
“This is an important result,” Hughes said. “It’s the first time that we’ve seen magnetic fields this late in the process of star and planet formation. And like any good scientific result, when you find something new it opens up whole new sets of questions we can ask.”
In fact, Hughes said the astronomers did not expect the results they got. “I honestly didn’t think it was going to work – we had been trying so long with Class II sources and hadn’t found anything,” she said. “But I thought, we might as well try this last source that is just a little younger than most Class II sources. You want to try everything you can – but it was really a surprise when it worked.”
The paper, “Spatially resolved magnetic field structure in the disk of a T Tauri star,” was published Oct. 22. Nature is the world’s most highly-cited interdisciplinary science publication. The 145-year-old journal is published weekly.
This NASA image shows a solar storm in early 2012.
A July NASA report that a huge solar storm narrowly missed Earth in 2012 – avoiding catastrophic damage to energy, transportation and communications systems – has caused a media stir and some worry among Earthlings.
What’s more, other recent reports say that Earth is overdue for a devastating storm of the kind known as a “Carrington event” after an 1859 storm that disrupted telegraph signals and caused other damage in a still-nascent industrial world. Named for 19th-century English astronomer Richard Carrington, it was the largest of its kind on record. A similar event now, in a world dependent on digital communications and electrical energy, would cause widespread, long-lasting power outages and disrupt transportation and communications planet-wide. Eric Mack, a science blogger for Forbes, referred facetiously to a reversion to “Amish-style” civilization.
Seth Redfield, assistant professor of astronomy, says the recent near-miss isn’t a cause for worldwide freakout, but should be a wake-up call; while a catastrophic solar storm may be several generations away, “it’s going to happen,” and scientists should be working on ways to better predict the event.
“I think it’s really important for us to understand what’s going on and have some good perspective on that because if we don’t prepare for it, we’re going to suffer the consequences,” he said. “We don’t need a Manhattan-style project and (to) devote 10 percent of our GDP to this one. But we do need to pay attention.”
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The almost-century-old 20-inch Van Vleck Refractor, which lives on Foss Hill in its iconic dome, is undergoing a major renovation. Work began June 2.
The rare historic telescope will be dismantled, cleaned, repaired, reassembled and modernized over a period of about 15 months in preparation of the observatory centennial in 2016. The refractor has been deteriorating gradually since its retirement from research around 1993.
Antique Telescope Society members and Ray Museum Studios founders Fred Orthlieb, Ph.D. and Chris Ray are leading the renovation. Astronomy major Julian Dann ’17 and German Studies major Rebecca Hanschell ’16 are assisting with the project this summer.
Read more about the project in this News @ Wesleyan article.
Photos of the renovation, taken on June 5, are below. (Photos by Olivia Drake)
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Astronomy graduate student Nicole Arulanantham received the Chambliss Medal by the American Astronomical Society.
Nicole Arulanantham, who is entering her second year as a graduate student in the Astronomy MA program, was awarded a Chambliss Medal by the American Astronomical Society at its June 3 meeting in Boston. The awards are given to recognize exemplary research by a student presenting a poster paper at an AAS meeting.
Arulanantham worked on the study with her advisor, Bill Herbst, the John Monroe Van Vleck Professor of Astronomy, chair of the Astronomy Department, and Ann Marie Cody of the California Institute of Technology. It involved analysis of data obtained with the Spitzer Space Telescope. Read more about the study online here.
Astronomy major Ben Tweed ’13 also presented a paper at the AAS meeting and reported results of his study of the local interstellar medium using data from the Hubble Space Telescope. His advisor is Seth Redfield, assistant professor of astronomy, and the work was done in collaboration with astronomers at the Universities of Warwick and Kiel, as well as University College London. Read more about the study online here.
Wesleyan’s 20-inch refractor telescope, located inside the Van Vleck Observatory on Foss Hill, will undergo renovations for the next 15 months. (Photos by Olivia Drake)
Beginning June 2, the nearly century-old 20-inch Van Vleck Refractor, which lives on Foss Hill in its iconic dome, will get a complete facelift to return it to full working order. The rare historic telescope will be dismantled, cleaned, repaired, reassembled and modernized over a period of about 15 months in preparation of the observatory centennial in 2016. (View several photos of the renovation here.)
The work will be done by Fred Orthlieb, Ph.D. and Chris Ray, members of the Antique Telescope Society who run a company called Ray Museum Studios. Based in Swarthmore, Penn., they are well-regarded experts in the highly-specialized field of antique telescope restoration; Orthlieb is the Isaiah V. Williamson Professor of Civil and Mechanical Engineering at Swarthmore College.
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Biology Ph.D candidate Sarah Kopac was invited to speak at the 2014 Spring Symposium of the Space Telescope Science Institute on the campus of Johns Hopkins University in Baltimore, M.D. on April 29. Kopac spoke on “Specialization of Bacillus in the Geochemcially Challenged Environment of Death Valley.” Watch a video of her 20 minute presentation online here.
Kopac’s talk was part of a four-day interdisciplinary meeting titled “Habitable Worlds Across Time and Space” featuring speakers from around the world working in such diverse fields as biology, geology and astronomy. The focus of the seminar was on identifying places within our Solar System and Galaxy where we can most profitably search for life beyond the Earth.
Astronomy major Raquel Martinez, MA ’13 and William Herbst, the John Monroe Van Vleck Professor of Astronomy, director of graduate studies, also attended the conference.
Both Kopac and Martinez were active active participants in Wesleyan’s Planetary Science Group seminars and activities. Kopac’s advisor is Fred Cohan, professor of biology, professor of environmental studies. Martinez’s advisor was Seth Redfield, assistant professor of astronomy.
Biology Ph.D candidate Sarah Kopac speaks at the the Space Telescope Science Institute’s Spring Symposium.
Raquel Martiniz MA ’13 poses with her research poster and conference organizer John Debes. Raquel is currently working in NASA’s Goddard Spaceflight Center and has been accepted to the Ph.D. program at the University of Texas where she will begin studies in the fall.
Meredith Hughes, assistant professor of astronomy, received a grant from the National Science Foundation to support her research on “Dust and Gas in Debris Disks Reveal the Origins of Planetary Systems.” The grant, awarded on April 21, is worth $532,943.
Hughes’ research focuses on understanding the formation and evolution of planetary systems. She particularly studies the huge disks of gas and dust surrounding a young star, which can give insight into how and when a star planet might form. The disk is made up of “junk” left over from the star’s formation.
The main technique Hughes uses to observe these circumstellar disks involves collecting radio waves. Invisible to the human eye, radio light allows astronomers to peer into dense dust clouds and trace the motions of small molecules.
Read more about Hughes’ research on planetary system formation in these past articles:
With his Wesleyan undergraduate and graduate students, Assistant Professor of Astronomy Seth Redfield studies exoplanets, the local interstellar medium, and stellar and exoplanetary atmospheres. He talks about the unique opportunity offered through his exoplanet program at Wesleyan, in which students at the undergraduate level participate in cutting-edge research.
Bill Herbst, the John Monroe Van Vleck Professor of Astronomy, director of graduate studies, received a $5,000 grant from NASA’s Jet Propulsion Laboratory to support observations with the Spitzer Space Telescope. The title of the proposal is “Planet Formation in the Circumbinary Disk of KH 15D.”
Herbst and his colleagues are measuring the brightness of the T Tauri binary system KH 15D covering several important missing orbital phases around minimum light and one near maximum. Data is crucial to understanding the mechanisms behind the observed reddening in the system, which has implications for planetformation and disk evolution.
Learn more about this study online here.
Meredith Hughes, assistant professor of astronomy, is the co-author of a paper titled “Molecular Gas Clumps from the Destruction of Icy Bodies in the β Pictoris Debris Disk,” published in the journal Science on March 6. Read more about Hughes study in this Wesleyan Connection article.
Meredith Hughes, assistant professor of astronomy, works with students on a small radio telescope, located on the roof of the Van Vleck Observatory.
A curious mix of dust and gas surrounding a distant star presents a unique mystery – and possibly a front-row seat to planet formation, according to Assistant Professor of Astronomy Meredith Hughes and colleagues, whose paper on the star appears in the March 6 edition of the journal Science.
The group of astronomers, including Hughes and 13 others, were the first to identify the asymmetry and “lumpy” quality of the gas surrounding beta Pictoris, using data from the Atacama Large Millimeter/Submillimeter Array (ALMA) in Chile. The discovery leads to two possible explanations: There may be a giant “exoplanet” lurking nearby (forcing clumps of carbon dioxide to orbit the star on opposite sides) or there has recently been a collision between two Mars-sized bodies. More data must be analyzed to figure out which event happened.
“We actually already knew that there was gas around this star, but we didn’t know how much, or that the gas would be lumpy and asymmetric – the asymmetry is another indication that the gas was probably generated by a recent collision,” explained Hughes.
Beta Pictoris, which is actually a stellar neighbor of Earth, about 60 light years away, is in an active place for planet formation, Hughes said. And the evidence discussed in the Science paper points toward very recent (on astronomical timescales – in this case probably thousands of years) events.
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