Banneker Institute: Days 1 & 2

Some time last fall, after a full day of class, work and rugby practice, I opened an email from my advisor, Professor John Johnson.  I was pretty tired, so it took me a few tries, but I eventually figured out that the email was an invitation to be part of the inaugural class for the Banneker Institute, a program designed to prepare talented students from underrepresented backgrounds for competitive graduate programs.

Now it's over half a year later and the program has finally started.  Here's (a brief) account of what's happened over the last two days.

The first day started off with introductions. So. Many. Introductions.  That's good, though, because I now understand Professor Johnson's motivations for starting this program and a know all of the student mentors' names and research topics.

After lunch, we students met with our research advisors. I'll be working with Dr. David Kipping on measuring the eccentricities of the five planets in Kepler-186.  I learned in the reading I did in preparation for this project that a planet's eccentricity greatly influences its climate.

$\Delta T = \left ( \frac{T_*^4 R_*^2}{4a^2} \right )^{1/4}\left [ \left ( 1-e \right )^{-1/2}-\left ( 1+e \right )^{-1/2} \right ]$

So, the more eccentric (or the more elliptical-y) an orbit, the more its temperature will change throughout its year.  Can you imagine what life would be like if your hometown went from feeling like the Sahara Desert to feeling like the Arctic Circle in a few months? It wouldn't be all that great. We should all take a moment to thank Earth and it's low-ellipticity orbit for not subjecting us to such extreme changes. 

Moment over? Okay. So that's pretty cool, but how am I actually going to find the planets' eccentricities? That's an excellent question, and I don't really know the full answer yet. But I do know that one of the first steps is producing what we call a Transit Light Curve.  (For more info on light curves, see this old post.)

If you followed that link, you saw that I've worked with light curves before, but I've never made one. I've only analyzed ones that were made for me.  It turns out that making them isn't as easy as you might think it would be.  

I started with a list of times and a list of flux measurements associated with each time. That gave me this plot:

 This is a mess! I can't see anything useful in that, so I had to play around with it a bit. 

By knowing the period of each planet's orbit, I was able to pick out all of the transits for each individual planet and stack them on top of each other respectively in a process we call Folding. For example, I identify all of the transits for planet d and stack, or fold, them on top of each other to make it look like a single transit:

And that's my first light curve!! Well, one of five firsts. 

Hopefully I'll continue to make progress so I can tell you all about it.  So if you're interested in exoplanets, galaxy mergers, or science fiction writing (the latter two are the other projects I'll be working on this summer), this blog is for you. If you aren't, this blog is still for you because there's a chance it might change your mind.