Tag Archive for Herbst

Sumarsam, Gruen, Herbst Honored with Faculty Research Prizes

Three Wesleyan faculty were honored with the Wesleyan Prize for Excellence in Research in October. The third annual prize is similar to the Binswanger Prize for Excellence in Teaching, but is presented to members of the faculty who demonstrate the highest standards of excellence in their research, scholarship, and contributions to their field.

Each recipient received a plaque and citation as well as research funds for their award.

This year’s recipients include: Division I, Sumarsam, Winslow-Kaplan Professor of Music; Division II, Lori Gruen, William Griffin Professor of Philosophy; and Division III, Bill Herbst, John Monroe Van Vleck Professor of Astronomy.

Students, Faculty, Community Observe Rare Complete Transit of Mercury

Visitors use telescopes outside observatory

Individuals gathered outside Van Vleck Observatory to view the transit of Mercury on Nov. 11.

For only the seventh time since Wesleyan’s founding, the planet Mercury passed directly in front of the sun, from the perspective of Earth—and Wesleyan served as a gathering place from which to learn about and observe the event. Faculty and students from Wesleyan’s astronomy department, as well as others from the University and the greater Middletown community, gathered outside the Van Vleck Observatory on Nov. 11 to witness the transit through three telescopes.

The mild weather and partly cloudy conditions—particularly at the beginning and end of the transit (which lasted from 7:35 a.m. to 1:04 p.m.)—made for good viewings through the University’s general-purpose 8-inch telescope, as well as its hydrogen alpha solar telescope, which allows users to observe solar prominences. A second solar telescope, owned by John Sillasen, MALS’07, a local amateur astronomer and member of the Astronomical Society of Greater Hartford, was also available to use as part of the event.

Gilberto Garcia ’20, an astronomy and physics major, was assisting with one of the solar telescopes. “Just seeing Mercury in general is a pretty rare occurrence, so I was pretty excited about it,” Garcia said. Viewed from a telescope, Mercury appeared as a small dot on the sun’s surface.

Herbst and Greenwood in The Conversation: The Tell-Tale Clue to How Meteorites Were Made

Wesleyan faculty frequently publish articles based on their scholarship in The Conversation US, a nonprofit news organization with the tagline, “Academic rigor, journalistic flair.” In a new article, John Monroe Van Vleck Professor of Astronomy Bill Herbst and Assistant Professor of Earth and Environmental Sciences James Greenwood write about the model they’ve proposed for how the most common kind of meteorites form—a mystery that has dogged scientists for decades.

The tell-tale clue to how meteorites were made, at the birth of the solar system

April 26, 1803 was an unusual day in the small town of L’Aigle in Normandy, France – it rained rocks.

Over 3,000 of them fell out of the sky. Fortunately, no one was injured. The French Academy of Sciences investigated and proclaimed, based on many eyewitness stories and the unusual look of the rocks, that they had come from space.

The Earth is pummeled with rocks incessantly as it orbits the Sun, adding around 50 tons to our planet’s mass every day. Meteorites, as these rocks are called, are easy to find in deserts and on the ice plains of Antarctica, where they stick out like a sore thumb. They can even land in backyards, treasures hidden among ordinary terrestrial rocks. Amateurs and professionals collect meteorites, and the more interesting ones make it to museums and laboratories around the world for display and study. They are also bought and sold on eBay.

Despite decades of intense study by thousands of scientists, there is no general consensus on how most meteorites formed. As an astronomer and a geologist, we have recently developed a new theory of what happened during the formation of the solar system to create these valuable relics of our past. Since planets form out of collisions of these first rocks, this is an important part of the history of the Earth.

This meteor crater in Arizona was created 50,000 years ago when an iron meteorite struck the Earth. It is about one mile across. W. Herbst, CC BY-SA

This meteor crater in Arizona was created 50,000 years ago when an iron meteorite struck the Earth. It is about one mile across. (Photo by Bill Herbst, CC BY-SA)

The mysterious chondrules

Study by Herbst, Greenwood Presents New Theory on How Meteorites Formed

A paper by John Monroe Van Vleck Professor of Astronomy William Herbst and Assistant Professor of Earth and Environmental Sciences James Greenwood will be published in the September 2019 issue of Icarus, published by Elsevier. The paper is available online.

The paper, titled “Radiative Heating Model for Chondrule and Chondrite Formation,” presents a new theory of how chondrules and chondrites (the most common meteorites) formed. It suggests a new approach to thinking about these rocks that populate the meteorite collections on Earth. It includes both theory and experiments (completed in Greenwood’s lab in Exley Science Center).

These laboratory experiments demonstrate that porphyritic olivine chondrules, the most voluminous type of chondrule, can be made using heating and cooling curves predicted by the “flyby” model. View a schematic diagram here.

“The problem of how chondrules and chondrites formed has been around for decades—more than a century, really. We cannot yet claim to have solved the problem but we have provided a new idea about the solution that passes many tests,” Herbst explained.

The basic idea, Herbst said, involves heating of small fluffy “rocks” in space as they fly past molten lava eruptions on larger asteroids, during the first few million years of the solar system’s existence.

Herbst, Greenwood, and Postdoctoral Research Associate Keniche Abe, will present this research at meetings this summer in Europe and Japan.

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


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.