Tag Archive for Herbst

NASA Supports Planetary Origin Research at Wesleyan

Jim Greenwood

Jim Greenwood

Jim Greenwood, assistant professor of earth and environmental sciences, and Bill Herbst, the John Monroe Van Vleck Professor of Astronomy, professor of integrative sciences, have received a research award from NASA in the amount of $550,000 for a program titled “Experimental simulations of chondrule formation by radiative heating of hot planetesimals.”

The grant will allow Greenwood and Herbst to hire a post-doctoral fellow who will work in Greenwood’s lab in Exley Science Center to reproduce chondrules — small spherules of melted rock that formed early in the history of the solar system and hold clues to the origin of the planets.

“The origin of chondrules has been a cosmochemical mystery for many decades,” Herbst said.

Bill Herbst

Bill Herbst

Herbst and Greenwood received the support to test a new theory that they have proposed, known as the “flyby” model. In a paper to the journal Icarus published in 2016, the scientists showed that primitive solar system material irradiated by hot magma during a close flyby of a planetesimal with incandescent lava on its surface could be responsible for the formation of at least some chondrules.

The grant, which comes from the NASA program “Emerging Worlds,” will allow them to test this theory in detail.

Their interdisciplinary research grew out of a seminar series sponsored by the Planetary Science group, which is rooted in the Astronomy and E&ES departments, but has a wide following among faculty in other science and non-science departments at Wesleyan.

Thesis Research by Arulanantham MA ’15 to Appear in Astronomy Journal

Bill Herbst, the John Monroe Van Vleck Professor of Astronomy; Martha Gilmore, the George I. Seney Professor of Geology; Wilson Cauley, a post-doctoral fellow; and Nicole Arulanantham MA ’15 are the co-authors of a paper forthcoming in The Astrophysical Journal.

The paper is based on Arulanantham’s thesis research at Wesleyan. The paper also was featured in the December newsletter of the Gemini Observatory, an international observatory based in Hawaii and Chile.

“The subject of the paper, a star known as KH 15D, was recognized as an important and interesting object in the 1990s through observations made on the Wesleyan campus by undergraduate and graduate students,” Herbst explained.

Arulanantham earned a master’s degree in astronomy and is now a graduate student in the astronomy department at the University of Colorado Boulder.

Herbst, Greenwood Co-Author Article on Chondrules

Bill Herbst

Bill Herbst

Bill Herbst, the John Monroe Van Vleck Professor of Astronomy, and James Greenwood, assistant professor of earth and environmental sciences, co-authored an article published in the planetary science journal Icarus. Their article, “A New Mechanism for Chondrule Formation: Radiative Heating by Hot Planetesimals” grew out of research seminars from the recently introduced Planetary Science graduate concentration and minor at Wesleyan.

Their work focused on chondrules, or tiny spheres of molten rock that permeate primitive meteorites and date to very close to the beginning of the solar system.

For decades, the existence of chondrules has puzzled astrophysicists and cosmochemists as no obvious heat source exists at the time and location of their formation. Herbst and Greenwood set out to find this elusive heat source by combining their expertise in astronomy and earth science, respectively.

Jim Greenwood

James Greenwood

“It could be that the heat source is hot lava — oceans of magma– that may appear on nascent planets in their earliest days. The heat source is radioactive decay of a short-lived isotope of Aluminum, incubated in planetesimals with the size of small asteroids and brought to the surface as molten rock,” Herbst said.

Most of the material available for planet formation ends up on a planet very early on. A few “lucky bits,” represented by the primitive meteorites, avoided collision with a planet until just recently.

“It is, perhaps, not surprising that many, if not all of them, had a close encounter with a hot planetesimal that produced the chondrules and, likely, the chondritic meteorite in which they are embedded,” he said.

Wesleyan’s Astronomical History featured in Astronomy Magazine

astronomymag

Astronomy magazine has an in-depth feature in its October issue on Wesleyan’s astronomical history and the restoration of its century-old, 20-inch refractor telescope, just in time for the Van Vleck Observatory’s centennial observation this spring.

Telescopes like Wesleyan’s 28-foot-long, two-ton refractor had once been cutting edge, and a source of pride for dozens of American universities. But as they “staggered into obsolescence” over the past half century, institutions have had to make tough choices about whether to renovate or retire them. In 2014, Wesleyan hired Chris Ray and Fred Orthlieb of Pennsylvania to give its refractor a second life.

The story traces the history of giant refractors through the 18th and 19th centuries, and Wesleyan’s acquisition of its own telescopes, and how they were used.

astronomymag2“Astronomical research and the teaching of students would go hand in hand at Wesleyan, [astronomer Frederick] Slocum told his audience (at the observatory’s dedication). But in an age of giant telescopes, even a 20-inch refractor was only modest. Worse still, New England’s weather is notoriously dreadful for astronomers. To make an impact, the Van Vleck Observatory would have to focus on a single fundamental question. By collaborating with Yerkes, England’s Royal Greenwich Observatory, and a consortium of other schools, Wesleyan researchers would measure parallaxes–a way to gauge how far away stars are through the tiny displacements in their positions caused by Earth’s orbital motion around the Sun. The astronomers would find the distances to the stars, Slocum said–and that’s exactly what they did.”

Wesleyan’s refractor was used to work on this problem from the 1920s through the 1990s, and it trained generations of young astronomers during that time. “In the 1950s, popularizer Walter Scott Houston peered through it to write his ‘Deep Sky Wonders’ column for Sky & Telescope.

Read the full story, which features a six-page spread of photos taken by Wesleyan photographers Olivia Drake MALS ’08 and Laurie Kenney, here.

Kopac, Herbst, Martinez MA ’13 Attend Space Telescope Science Institute Symposium

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.

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.

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.

NASA Grant Supports Herbst’s Observations with Spitzer Space Telescope

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.

 

Redfield, Herbst Discuss Transit of Venus on Fox 61

Bill Herbst discusses the Venus transit on Fox 61 news.

On a feature for Fox 61, Seth Redfield, assistant professor of astronomy, and Bill Herbst, chair and the John Monroe Van Vleck Professor of Astronomy, discussed the transit of Venus across the Sun, and showed viewers how Wesleyan would be marking the event with public viewings from Van Vleck Observatory.

“So here we have a case, where we can see the affect of a planet on a star, close up,” Herbst said in the feature, which aired on June 5.

The next transit won’t happen intil 2017.

“It’s a very wonderful opportunity to learn something new about planets and their atmospheres and solar systems in general,” Redfield said.

Herbst, Kilgard Published in Astrophysical Journal

Bill Herbst, the John Monroe Van Vleck Professor of Astronomy, chair of the Astronomy Department, is the author of “Infrared Variability of Evolved Protoplanetary Disks: Evidence for Scale Height Variations in the Inner Disk,” published in The Astrophysical Journal, Volume 748, Issue 1, article id. 71, 2012.
Roy Kilgard, research assistant professor of astronomy, is the author of “Chandra Observations of the Collisional Ring Galaxy NGC 922,” published in The Astrophysical Journal, Volume 747, Issue 2, article id. 150, 2012.

Malamut’s Astronomy Research has been Out of this World

Craig Malamut ’12

In the summer of 2010 Craig Malamut traveled to the Easter Islands to study and photograph a rare solar eclipse. Soon after his eclipse observations were completed, NASA used one of his photographs in their official materials on the event. He also spent a week collaborating with astronomers from the University of Chile in Santiago to study Pluto’s atmosphere as it obscured the light from a faint star. This year, Malamut has coauthored two papers for astronomical journals and is analyzing data from the Hubble Space Telescope on gas and dust clouds lying near the sun and other nearby stars.

It’s the kind two-year research run that many scientists would be proud and excited to have accomplished. But Craig Malamut is not a paid researcher or a member of any faculty. He’s a college student who is still working through his senior year at Wesleyan.

Malamut, an astronomy major, has been working at an advanced level for someone who has yet to earn a bachelor’s degree. While the experience has been intense, he hasn’t been intimidated by the complexity of the work or felt limited by his undergraduate standing. “I’ve felt very prepared for this level of research from the courses, discussions, and advising I received from the astronomy department,” he says. “Professors Herbst, Moran, Redfield, and Kilgard do a great job getting their students involved early in astronomy research, whether at Wesleyan or abroad.”

He also took part in the Keck Northeast Astronomy Consortium Research Experience for Undergraduates (KNAC REU) Williams College. Several members of astronomy faculty also recommended him for the Keck-sponsored program in the Easter Islands.

Herbst, Capelo Papers in Astronomy Publications

Bill Herbst, the John Monroe Van Vleck Professor of Astronomy, is the co-author of “The Highly Dynamic Behavior of the Innermost Dust and Gas in the Transition Disk Variable LRLL 31,” published in The Astrophysical Journal, Volume 732, Issue 2, article id. 83 in 2011, and “Preliminary Analysis of MOST Observations of the Trapezium,” published in American Astronomical Society, AAS Meeting #218, #96.05; Bulletin of the American Astronomical Society, Vol. 43 in 2011.

Herbst and his graduate student Holly Capelo are the authors of “Optical And Infrared Monitoring Of KH 15D,” published in the American Astronomical Society, AAS Meeting #218, #226.08; Bulletin of the American Astronomical Society, Vol. 43 in 2011.

Herbst to Serve as Director of Graduate Studies

Bill Herbst

Bill Herbst, the John Monroe van Vleck Professor of Astronomy, will serve as director of graduate studies, beginning this fall 2011 through spring 2014.

Herbst received his B.A degree from Princeton University, his M. Sc. and Ph.D. degrees from the University of Toronto and has taught at Wesleyan since 1978, often serving as chair of the Astronomy Department and as director of the Van Vleck Observatory. In 2003, he received the Wesleyan Alumni Association’s Binswanger Award for Excellence in Teaching. He has recently served on the Advisory Committee, as chair of the Merit Committee, as vice-chair of RAB and, over the years, on many other faculty committees including the Faculty Planning Committee and as chair of the Student Affairs Committee.

As an astronomer who studies the formation and evolution of young stars and protoplanetary disks, his discoveries have been featured prominently in the journals of his field as well as the popular press. He is particularly known for his work on T Tauri stars, sun-like stars surrounded by disks in which the formation of planets is either already proceeding or imminent. With collaborators at the Max Planck Institute in Germany he has led the world in the discovery of rotation rates of young stars and elucidated the rotation history of sun-like stars from their earliest times. His work has been presented in many venues including the prestigious Protostars and Planets V conference hosted at the University of Hawaii in 2007.

In 1995, with graduate student Kristin Kearns, he discovered, based on observations at Wesleyan, a unique star system now known as KH 15D whose behavior continues to astound astronomers, while informing studies of terrestrial planet formation. In collaboration with his (physics) Ph.D. student Catrina Hamilton, now a faculty member at Dickinson College,

Herbst Receives NSF Grant for Astronomy Consortium

Bill Herbst

Bill Herbst, the John Monroe Van Vleck Professor of Astronomy, received a grant for $471,990 from the National Science Foundation. The grant will provide summer research stipends for students and funds for an Annual Undergraduate Research Symposium with the Keck Northeast Astronomy Consortium (KNAC).

KNAC is a group of consisting of Wesleyan and seven other institutions (Colgate, Haverford, Middlebury, Swarthmore, Vassar, Wellesley and Williams) that have worked together to improve research experiences for undergraduate astronomy majors.

KNAC was formed 20 years ago with a seed grant from the W. M. Keck Foundation and has been supported in recent years by the NSF. Hundreds of students have been served during this time and many are now professional astronomers or scientists in other fields, Herbst says.