Undergraduate Discovers Exoplanet Using Innovative Technique

July 26, 2011

Undergraduate astronomy majors at Ohio State have the opportunity to collect data at Kitt Peak National Observatory in Arizona, work on the latest instruments that will be used to obtain data from the world's most technologically advanced telescopes, and discover planets.

During her participation in the summer undergraduate research program of 2008, Julia Janczak discovered an exoplanet – planets that are not in our Solar System.

Since the first exoplanet found in 1992, there have been more than four hundred confirmed exoplanets. Of these four hundred, only ten exoplanets have been found with a technique known as microlensing. Janczak discovered the tenth and most recent.

Microlensing events occur when the light from a distant source is bent by the gravitational force of
a massive foreground object, such as a star or galaxy. By observing how sharply the light is bent,
astronomers can deduce information about the foreground object. This means that very faint objects,
such as planets or brown dwarfs can still be studied, even though they cannot be seen through a telescope.

Janczak collaborated with faculty member Professor Andrew Gould who is a Distinguished Professor of Mathematical and Physical Sciences at Ohio State. Her goal for the 2008 summer astronomy research program at Ohio State was to analyze data from a microlensing event. “She was involved with the data reduction as well as trying to understand the microlensing events as they were coming in,” explained Gould.

Ironically, neither Gould nor Janczak expected a planet to be found from the data. “The event just
looked like a single-star microlensing event, and part of the reason for analyzing it was due to its
apparent lack of planets,” said Gould.

Janczak worked on her research throughout her senior year, and presented her work at the Biological.
Mathematical, and Physical Sciences Research Forum and at the Denman Forum. Both of these forums
are OSU sponsored and give undergraduates a chance to present a poster about a research project they
have been involved with.

After much hard work and time spent, Janczak published a paper describing her work, "Sub-Saturn
Planet MOA-2008-BLG-310Lb: Likely to be in the Galactic Bulge," as first author in March of 2010.
Gould remarked that, “Janczak's paper is probably one of the longest and most complex papers an
astronomy undergraduate has written.”

Janczak is currently a graduate student at the Department of Physics at Ohio State. “I have profound
respect for Dr. Gould and the additional collaborators Scott Gaudi, Richard Pogge, and Subo Dong ,”
said Janczak, “They were very helpful and a joy to work with. I had a wonderful experience.”

Searching for exoplanets via microlensing involves a global network of communication between
observational astronomers. This network is called the microlensing follow-up network, or MicroFUN.

“Ohio State is the world headquarters of MicroFUN,” Gould explained. “It's a worldwide network of
observers, where more than half of them are amateur astronomers.”

Gould continued his research with another undergraduate, Li-Wei Hung, during the summer of 2010.

Hung participated in the Smithsonian Astrophysical Observatory undergraduate research program in
Cambridge, Massachusetts, during the summer of 2009. “I analyzed the accretion disc around an X-ray pulsar within a binary system and tried to understand the significance behind its geometrical orientation to the pulsar,” said Hung. “My time at Harvard equipped me with skills and knowledge that I continue to use in my current research. It was an invaluable experience.”

The following winter Hung traveled to Chile. There she participated in the Cerro Tololo Inter-American Observatory research program where she performed data analysis on three different galaxy clusters. “The CTIO research program was a lot of fun. I worked with a Chilean student who taught me programming in python, which turned out to be a very helpful skill that I’m using in my current research with Dr. Gould.”

Hung presented her summer research at the Biological, Mathematical, and Physical Sciences Research
Forum in 2010 and won first place in her category.

Hung’s knack for undergraduate research lead her to apply for the Ohio State’s Astronomy REU for the
summer of 2010. Her interest in planetary science made her a good match for Gould.

“My research at Ohio State was the hardest work of the three REUs I have undertaken. Analysis of
a microlensing event involves long, complex computer codes which I am expected to modify to fit
my event’s specifications,” said Hung. “I will continue to work on this interesting event and write my
senior thesis on it,” she added.

Hung graduated at the end of winter quarter 2011 with research distinction in astronomy. She is continuing in astronomical research as a graduate student at UCLA.

Written by Jessica Orwig