Tag Archive for Astronomy Department

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.

Redfield Participates in NASA’s IBEX Mission Press Conference

Seth Redfield, assistant professor of astronomy, speaks at a press briefing about NASA's IBEX (Interstellar Boundary Explorer) spacecraft, which sampled multiple heavy elements from within our solar system and beyond. IBEX found some astonishing data in the process.


Seth Redfield had to cut short his first Astronomy 224 class of the 2012 spring semester, but he had a good excuse: he was presenting at an international press conference being held by NASA on one of its recent missions.

Redfield, an assistant professor of astronomy, was chosen by NASA to be a non-mission expert to help verify results from the space agency’s ongoing IBEX (Interstellar Boundary Explorer) mission, an unmanned probe that analyzes the interstellar boundary that protects much of our solar system, including the Earth, from deadly cosmic rays from interstellar space.

One of Redfield’s primary areas of research deals with these types of clouds, more generally known as local interstellar medium (LISM), and his models had been used by NASA in the past,

Institute Supports Redfield’s Cool Star Winds Research

Seth Redfield

Seth Redfield, assistant professor of astronomy, received a grant worth $65,932 from the Space Telescope Institute to support a project titled, “Cool Star Winds and the Evolution of Exoplanetary Atmospheres.” The grant expires in October 2014.

Redfield is observing stars that are host to their own planetary systems.  These “exoplanets” were only discovered in the last decade or so, and since their discovery, astronomers are very interested in learning more about the properties of these planets and their atmospheres.

“Invariably, the study of exoplanets is really an exercise in putting life on Earth into a cosmic context.  How common are planets?  Are these planets ‘habitable,’ which is just shorthand for, could liquid water exist on this planet? This project seeks to address the important relationship between a planet/atmosphere and its host star,” Redfield explains.

Scientists know that the host star plays a major role planets and their atmospheres, and the diversity of stars in our galaxy is quite extreme.  One way that stars influence their planets is through a stellar “wind,” which is composed of charged particles that escape the gravitational field of the Sun and travel out into interplanetary space. When solar wind interacts with the Earth’s magnetic field, it creates aurora borealis.The solar wind might have been so strong when the Sun was young, that it could have effectively sand-blasted an entire planetary atmosphere away, particularly if that planet did not have a strong magnetic field,” Redfield says. This may have happened with Mars, which does not have a strong global magnetic field like Earth does.
This would explain why we see ancient evidence of surface water, which implies Mars had a substantial atmosphere at the time, but today, Mars is arid and has a very minimal atmosphere.
“The observations I plan to do will measure the interaction of stellar winds with the surrounding interstellar gas and dust.  This will give us a handle on the strength of the stellar wind, and enable us to explore the impact of these winds on the planets that are currently around these stars,” he says. “These stars are ‘cool’ not only because they are incredibly amazing to study, but because their surface temperatures are on the lower side compared to other stars we observe.”
The Sun is also a cool star.

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.

NASA Supports Moran’s Black Hole Research

Ed Moran, associate professor of astronomy, received a grant worth $62,804 from NASA for a project titled “Black Holes at the Center of Nearby Dwarf Galaxies.”

The project involves observations of six dwarf galaxies with the Chandra X-ray Observatory, also known as the “Hubble Space Telescope of X-ray Astronomy.”

“We have identified ‘active nuclei’ in these objects, which are powered by the accretion of gas onto massive black holes,” Moran says. “The X-ray emission associated with the accretion will give us direct information about the black holes and their surroundings in their host galaxies.”

The black holes in these galaxies are probably less massive than the black holes identified at the centers of larger galaxies (say, 10,000 to 100,000 times the mass of our sun in dwarf galaxies, as opposed to 10 million to 1 billion solar masses in big galaxies.

“By studying these ‘intermediate-mass’ black holes we hope to determine how the super-massive black holes originated back when the universe was young,” he says.

Malamut ’12 Published in Astronomy Journals

Craig Malamut ’12 helped photograph the Easter Island solar eclipse July 11 as a participant of the Williams College Eclipse Expedition. The composite image brings out the correlation of structures in the sun’s inner and outer corona.

Craig Malamut ’12 is the primary author of “High-Resolution Imaging of the 2010 Total Solar Eclipse at Easter Island,” which will be published in the Coronal Courant, an on-line journal for students maintained by the Solar Physics Division of the American Astronomical Society (AAS). The article describes some results from experiments done during the 2010 total solar eclipse, for which he traveled to Easter Island.

Malamut is also a co-author of  “Structure and Dynamics of the 2010 Jully 11 Eclipse White-Light Corona,” which was published by The Astrophysical Journal in its June 20 issue.

Malamut was supported by the Keck Northeast Astronomy Consortium’s REU program which is funded by the National Science Foundation through a grant to Wesleyan.

Craig Malamut '12

Read more about Malamut’s efforts photographing the eclipse in this Wesleyan Connection article.

Capelo Praises Wesleyan’s M.A. Astronomy Program in Astrobites

Holly Capelo, a graduate student in the Astronomy Department, wrote a contribution to “astrobites,” an e-newsletter for students and others interested in astronomy. In her article, titled “Careers, Like Space Missions, are Tricky: How a Master’s Degree Can Help,” Capelo writes about her experience as a M.A. student at Wesleyan:

“In general the program is quite flexible: the curriculum includes a baseline number of astronomy courses and the rest of the course work is custom fit for individual students’ backgrounds and goals; often the candidates have undergraduate degrees in related fields, such as math, physics and computer science, and acquire astronomy-specific research and academic experience during their time there. The small department is housed entirely in an antique observatory on a bucolic liberal arts campus.”

At Wesleyan, Capelo studies transition disks in young stellar objects at optical and near-infrared wavelengths. Her advisor is Bill Herbst, the John Monroe Van Vleck Professor of Astronomy. Read the entire article online here.

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.

Johnson ’11 Honored for Exoplanet Research

Marshall Johnson '11 presented his research poster at the American Astronomical Society (AAS) meeting, Jan. 10-13 in Seattle, Wash. The AAS awarded Johnson with the Chambliss Astronomy Achievement Award.

Marshall Johnson '11 presented his research poster at the American Astronomical Society (AAS) meeting, Jan. 10-13 in Seattle, Wash. The AAS awarded Johnson with the Chambliss Astronomy Achievement Award.

Marshall Johnson’s research is out of this world.

For the past two years, the senior astronomy major used the Van Vleck Observatory’s 24-inch Perkin Telescope to study the transits of “exoplanets,” or planets outside our solar system, that orbit another star.

His study, titled “First Results from the Wesleyan Transiting Exoplanet Program,” explains a refined orbital period of a newly-discovered planet named WASP-33b (Wide Angle Search for Planets). Ultimately, Johnson may prove that he’s discovered another planet, WASP-33c.

“Here in Connecticut, with clouds and haze, we don’t have the best observing conditions, but I was still able to obtain high-quality data using our modest-sized telescope,” Johnson says. “The most interesting result, which is still tentative, is that I am seeing transit timing variations in one target. This could be due to an additional planet in the system.”

For his efforts, the American Astronomical Society (AAS) awarded Johnson a Chambliss Astronomy Achievement Award, which “recognizes exemplary research by undergraduate and graduate students.” Awardees are honored with a Chambliss medal

Telescope Science Institute to Support Redfield’s Cool Stars Project

Seth Redfield

Seth Redfield, assistant professor of astronomy, received a $55,973 grant from the Space Telescope Science Institute to support the Advanced Spectra Library Project: Cool Stars.

The grant will allow Redfield to facilitate the analysis of data collected on the Hubble Space Telescope and travel to meetings to present the results. He will collaborate with 20 other researchers from around the world on the project.

“All astronomers, worldwide, put in proposals once a year to use the Hubble to get observations.  They get about 10 times more requests than they have time to give,” Redfield explains. “If you are approved, you send the details of the observations to them, they program them into the computer onboard the spacecraft, and then a couple weeks later you get an e-mail to download your data from the Space Telescope Science Institute web site.”

The project will receive data  from 150 orbits, which is 6 percent of all the time on the Hubble allocated to astronomers worldwide this year. These observations will produce a high quality spectroscopic atlas of eight sun-like, or “cool” stars, which will be used by the wider community for decades to come.

The immediate scientific research enabled by this project will involve magnetic activity, space weather, disk winds of young stars, red dwarf flares, erosion of exoplanet atmospheres, and the properties of the intervening gas and dust in Earth’s cosmic neighborhood.

The grant will support the Cool Stars program through Nov. 30, 2013.

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.