Sagan Postdoctoral Fellowship Recipients

2013 Postdoctoral Fellows

for additional information on each Fellow's project, please click on the project title

JPL press release announcing the 2013 Carl Sagan Fellows

Jared Males
University of Arizona

Blazing the Trail: Imaging Extrasolar Giant Planets in the Habitable Zone

Jared is 37, and grew up in Brookings, SD. He attended the University of Nebraska, Lincoln, where he majored in Physics. He served in the U.S. Navy for 7 years as a submarine officer, and later worked at the Johns Hopkins University Applied Physics Lab as a project manager and analyst. He will receive his PhD from the University of Arizona in August, 2013.

Jared thinks "the search for extraterrestrial life is one of the most compelling scientific quests we have ever undertaken, and developing the ability to characterize habitable extrasolar planets is a fundamental requirement for this search". The goal of his research is to image Jupiter and Saturn sized planets in the liquid water habitable zone of nearby stars. These planets will be warmed by the star's radiation, making them bright in the thermal infrared. With the high contrast and high resolution achieved by the Magellan and Large Binocular Telescope adaptive optics (AO) systems, we can detect this heat. With Magellan AO, we can also work in visible light - taking the highest contrast and highest resolution images of the nearest sun-like stars ever taken at visible wavelengths. These observations will allow us to study how AO works in this regime, and prepare us for the next generation of extremely large telescopes which will be sensitive to even smaller planets.

Katja Poppenhaeger
Harvard-Smithsonian Center for Astrophysics

Understanding Exoplanet Systems Through High-energy Observations

I received my PhD from Hamburg University (Germany) in May 2011 and am 32 years old; I grew up near Frankfurt, Germany.

I became interested in physics early on, and at age ten one would have most likely found me curled up in my room with a particle physics book for kids. Later, I went to Frankfurt University to study theoretical physics. After earning my masters degree I spent a few years outside academia as an environmental scientist. A long journey across Australia with its crystal clear night skies and various radio telescopes helped me find my true calling as an astrophysicist.

For my Sagan fellowship, I will investigate how stars and their close-in planets influence each other's evolution over time. Massive exoplanets may affect their host star's spin and magnetic activity, while the host star's high-energy emission can drive atmospheric evaporation of the planet. I will use high-energy observations to study the rotational history of planet-hosting stars and how their magnetic activity evolution has influenced the mass spectrum of exoplanets we observe today.

Avi Shporer
Jet Propulsion Laboratory

Using Kepler to Discover Non-transiting Massive Planets Orbiting Stars Across the Main Sequence

I was born in Philadelphia, PA, and grew up in Israel. I got my Ph.D. in 2010 from the Tel Aviv University. I was a postdoc at LCOGT and UCSB, and moved to Caltech in the summer of 2012.

I was fascinated by the revolutionary approach enabled by the beaming effect, of monitoring stellar radial velocity variations using photometry, instead of the traditional spectroscopic Doppler effect.

Brown dwarfs are rare objects, which are only rarely being detected by radial velocity and transit surveys. Kepler's high-precision and continuous data allows to detect short-period brown dwarf companions through the minute photometric orbital modulations they induce. Therefore, Kepler's large sample of stars will lead to finally mapping the mass distribution of short-period low-mass binary companions throughout the brown dwarf mass range.

Jacob Simon
Southwest Research Institute

Turbulent Disks: From Dust Grains to Planets

I grew up in Collinsville, IL, a small town 10 miles east of St. Louis and attended the University of Illinois graduating with a B.S. in physics. I then went onto the University of Virginia, where I did my graduate work, earning a Ph.D. in astronomy in the summer of 2010. I am currently a postdoctoral fellow at JILA and the University of Colorado in Boulder. I am 30 years old.

My interest in this project stems from a strong desire to understand the nature of solar system formation from first principles. I have spent my career to-date studying the nature of the gas-dominated protoplanetary disks that form planets, and now I want to make the next logical step and understand the formation of planets themselves. Starting from gas and dust and ending with orbiting planets, asteroids, etc., I want to see the big picture — how do planets form?

I will use numerical simulations run to understand the physics involved in planet formation. In particular, I plan to understand how turbulence, believed to be present in these disks from magnetic instability, affects the clumping of dust grains into early planetesimals, roughly 100 km in size. I will then further study the growth of these planetesimals to larger, protoplanetary sizes, again in the turbulent conditions that prevail in these disks. .clearfix

Jennifer Yee
California Institute of Technology

Measuring the Frequency of Massive Planets around M Dwarfs with Microlensing

I will receive my PhD in Astronomy from The Ohio State University in August 2013. I am 27 years old and I grew up in New Paltz, NY.

I knew I wanted to work on exoplanets when I started grad school because I'd watched so much Star Trek as a kid. For the first time, we are able to "explore strange new worlds," to start understanding the broad diversity of exoplanets and exoplanetary systems. Microlensing is a wonderful way to do this because it's capable of finding small planets far from their host stars that cannot be discovered any other way. It is also very exciting because microlensing happens in real-time and there is usually only one opportunity to find each planet.

I will use microlensing observations to test the core-accretion theory of giant planet formation, which predicts a low occurrence rate of giant planets around M dwarfs. Most of the lens stars probed by microlensing are M-dwarfs because they are the most common stars in our Galaxy, but the masses of the host stars are usually unmeasured for individual microlensing events. I will use adaptive optics observations to measure light from the lens stars to identify a sample of microlensing events due to confirmed M-dwarfs. From this sample, I will measure the occurrence rate of giant planets around M-dwarfs to find out if they are indeed rare, as predicted by core-accretion theory.