Summer to Fall

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Almost a year into the research, I was comfortably entering planets, looking forward to new ones getting announced. I went to a conference (more on this later), and I added some fields to the database structure, like the radius of the star. The Exoplanet Orbital Database paper had been submitted, accepted, and then published! 

Summer soon arrived. I wasn't able to edit the database until I returned to Penn State during the second summer session. July brought along my first time seeing fireflies. Such an experience may seem mundane to some, but I'd mainly lived in large cities before. The small orbs of light vanishing here and reappearing there made me think my eyes were tricking me. It was breath-taking for me, though it was the only time I saw them over this summer. Luckily, the one other event which thrilled me just as much remained more constant - the TERMS project.

While not all exoplanets transit, it is possible some do but their transits have not been detected. Finding the transits of these exoplanets is the goal of the Transit Ephemeris* Refinement and Monitoring Survey (TERMS).  Our contribution is the uncertainty of the transit times. I created files for individual planets that read in their velocity data, certain properties of the star, and, when ran, will use a program to refit the planet's orbit, calculate, and produce the next five predicted transit times and their uncertainties. The uncertainty gives a range for the astronomers who will use the prediction to look at the planet. At first I thought an error of two days seemed decent, but the idea of pointing the telescope at an object for several days is excessive and not ideal. We calculate the times for many planets; only a few will be good candidates to observe. 

Over the summer and during this fall semester, we modified the files so that they no longer return the transit times. Instead, they save the newly fitted orbits to a data file. Then, a program that Eunkyu wrote will take the parameters in the data file and generate a table with properties of the planets' systems as well as the five times with their uncertainties. A parallel application of the programs used for TERMS is calculating the secondary eclipse of transiting planets. Ming Zhao, Dr. Wright's post doc, joined our team this year, and he is interested in when a planet goes behind its star. 

You might ask, what is there to see? I certainly wondered. It turns out that when the planet is behind the star, the total brightness of the system decreases because the star blocks out the planet's radiation from us. When the plant transits the star, it is the other away around - the tables have turned. Knowing when the secondary eclipse happens will lead to knowing more properties of the planet, like its temperature and perhaps even its atmospheric composition. 

post 3.jpg
Source - NASA (Jonathan Fortney & Mark Marley)

On each floor of Davey Lab, where I work, you can find poster and graphics and, if you are on the fifth floor, riddles, that make walking down those hallways almost a hobby of mine. One poster, a copy of which I would love own, is of candidates of the Kepler mission (, featuring this image:

post 3 - kepler.jpg
Source - Jason Rowe

Our sun, with Jupiter transiting, is, for scale, by its lonesome toward the top right. 
You should visit the link and look for the URL of the picture in high resolution, because some of the planet candidates are rather small compared to their star. If you visit the high resolution image, you will be able see Earth in front of our sun. 

There are 1,235 candidates in the image. Simply hearing such a number may be impressive (and nerve-inducing for my hands, because how many of those will they have to help enter into the EOD? My mind, however, is certainly excited), but it doesn't compare to all of them, grouped together, presented for you to see. Say you were on one of the planets transiting one of the bigger stars - could you imagine what the sky would look like with such a large presence? 

Here is an animation of the multi-planet systems: 

Raise your hand if you stared at it without looking away. It is hypnotizing. 

*Ephemeris describes the time that an astronomical object will be at a location. Transit ephemeris, then, is when the planet passes right in front of the star. You can imagine how valuable knowing the timing and location of objects, as they describe the motion, and the motion is what, for example, the great laws of Kepler describe. 

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