Thursday, December 16, 2010

Be Vewy, Vewy, Quiet...I'm Hunting Pwanets!

And you can too. Another citizen science project from my friends at the Zooniverse lets you join in the hunt for planets orbiting other stars by analyzing their light curves. Planet Hunters lets you look at data from the Kepler satellite launched in 2009. Kepler is monitoring the brightness of over 150,000 stars in a small chunk of the sky near the constellation of Cygnus. Whenever a planet passes in front of the star, the star will get a little bit dimmer as some of its light is blocked. By looking at a graph of the intensity of light versus time, you can see a series of dips when planets pass in front of the star. Sounds simple right?

In principle, yes. However these dips in light are VERY small, only fractions of a percent. At this level, there is a lot of noise in the data. Computers can pick out some of the obvious candidates, but for complex light curves, even a basically trained human eye is better. Here is a sample of a light curve to analyze.

The interface asks questions to lead you through the analysis. You can see some dips but also some peaks in this one. The dips could be a planet or this could be a variable star. By identifying the dips, you start building up a pattern. If the pattern continues, follow up observations will be scheduled to determine if this is a planet or something else is going on here (even if its not a planet, I wouldn't be surprised at all if a couple of new types of variable stars are discovered in this project!)

There is a short tutorial you can go through to practice before you start looking for planets. You don't need to worry about messing up too much since they show each light curve to many people, so any mistakes should get averaged out.

What if you find a planet? Well, you don't get to name it as there are conventions for that already. However, if you register with the site they will offer to make you a co-author on the discovery paper. Then you can lord it over your friends that you got published in a science research journal!

For teachers out there, this can be used in the classroom as well. When you log in, they keep track of all the stars you classify so it is easy to see if students have done their homework. You can even go back and look at interesting stars again, so if a student finds something unusual, it is easy to show others.

This project comes with the usual discussion forums where you can discuss interesting objects with other users.

If you can read this, you can discover an extrasolar planet!

Reprinted with permission from the Half-Astrophysicist Blog.


kkdither said...

I looked at this the last time you posted this. I had no clue what I was doing.

I've come to the realization that if I could more readily identify "dips," my life would be much, much easier.

Anonymous said...

Is Venus taken yet? If not DIBBS!