The Life of a Grad Student at NASA

• By Korey Haynes
• March 7, 2013
• Comments Off on The Life of a Grad Student at NASA

I’m Korey Haynes, a graduate student doing research here at Goddard for my PhD thesis. What does a graduate student do at Goddard? Until recently, I spent about half my time taking classes and working on schoolwork, and the rest of the time conducting research here with my adviser. Now that I’ve completed all my classes – and passed the dreaded qualifying exams – I’m working on research full time.

While a lucky few people start grad school knowing exactly what they want to study, and many people come in totally undecided, I fell into a third category – I thought I knew exactly what I wanted, and then completely changed my mind. When I started grad school, I was going to study galaxies. Galaxies, of course, were the best area of astronomy. They have the prettiest pictures by far, they’re some of the biggest things you can study, and there are all sorts of still open questions. Plus I had already been to the Very Large Array in New Mexico as an undergrad to observe one galaxy, and I was getting to use Arecibo, the world’s largest single dish telescope, to help collect data on a large survey of galaxies during my first year in grad school, and I found all that observing to be very exciting.

Me, middle, visiting the Very Large Array as an undergrad with my classmates.
Credit: Korey Haynes

But during that first year, I realized that instead of pondering the really interesting questions about galaxies, I liked reading articles about exoplanets. Kepler was just starting to return results, and it seemed like exoplanets were exploding as a field. Not only were we finding more planets than we could have dreamed of ten years before, we were starting to get observations of the atmospheres of some of these planets. We were observing the atmospheres of planets lightyears away!

Unfortunately, no one at my university studied exoplanets. On the advice of a supportive professor, I looked up people studying exoplanets at other, nearby institutions, and sent out some emails. I honestly didn’t know what to expect. Cold calling people is always nerve wracking, and surely these scientists were busy with their own research, and wouldn’t want to spend the time or funding to hire someone from nothing more than a random email. But after a surprisingly short amount of time, I got in touch with my current adviser, Avi Mandell, who was happy to take on a grad student. Finding funding took a bit longer, but I had started early, and by the beginning of the following school year, I had a desk at NASA. In astronomy, as in all fields, never underestimate the power of simply asking for opportunities. You can find yourself in some surprisingly awesome places.

Now I get to work at what my adviser has called the “bleeding edge” of exoplanet studies. We take infrared observations of exoplanets that transit their host star. A planet transits when it passes between us and the host star, and blocks some of the light from the star. We can also view what we call secondary eclipses, when the planet moves behind its star, and the light from the planet itself is no longer visible. This is easier to see at longer wavelengths, because the ratio of the star’s light to the planet’s is smaller at longer wavelengths. By looking at how much light the planet blocks, we can tell how big the planet is. By measuring the light from the planet itself, we can tell how how hot it is, and by measuring how the amount of light blocked by the planet changes at different wavelengths, we can tell what the atmosphere is made of.

When the planet is next to its star, from our perspective, we can see the combined light from the planet and star. When the planet passes in front of its star, it blocks some light from the star, and the light we see dips–we call this a light curve. A shallower light curve is seen when the planet passes behind its star, and the light from the planet itself is lost.
Credit: NASA Ames

This shows how the eclipse depth can change at different wavelengths, due to the absorption or emission of molecules in the atmosphere. Image taken from Stevenson et al. (2010).
Credit: NASA/JPL-Caltech/K. Stevenson (Univ. of Central Florida)

In particular, we look for the strong infrared bands formed by water, methane, and carbon monoxide. But your measurements need to be very precise, because the slightest hiccup in the host star or the telescope instrumentation can introduce huge challenges to interpreting your results. So far I’ve been using spectra taken with the Wide Field Camera 3 (WFC3) on Hubble, and I got to travel to Hawaii to observe using a new spectrometer called MOSFIRE on Keck. I’m still checking off my list of using all the “Biggest” telescopes in the world.

Me with the Keck twin telescopes behind me to the left.
Credit: Korey Haynes

Aside from research, I like to do public observing, either with my school or, more recently, with the National Air and Space Museum’s public observatory. I love sharing my knowledge with the public, and getting other people excited about astronomy. When research gets frustrating—and it always does, from time to time—it’s great to just look at sunspots or craters on the moon with a little telescope. Seeing other people’s excitement at those things is always enough to remind me why I started doing astronomy in the first place: because it’s awesome.