1. Probing for Puny Planets Nick Cowan (for Eric Agol) October 19, 2006 Nick Cowan (for Eric Agol) October 19, 2006

2. Extrasolar Planets … are planets orbiting other stars. We’ve discovered some 200 of them. They’re mostly in tight orbits (days/weeks) They’re mostly pretty big (Jupiter-sized). The small (Earth-sized) ones are the ones we’d like to know about. Small planets are hard to detect.

3. Transiting Planets A very small number (10 or so) of the known extrasolar systems happen to be oriented so that the planet passes in front of its host star.

5. Orbital Resonance …is like pushing someone on a swing As long as you always push them at the same point in their swing, they’ll go higher and higher…

6. Detecting Small Planets If even a little planet happens to be in an orbital resonance with a giant planet planet, it will cause a noticeable shift in the giant planet’s orbit! This shift will change the transit time of the giant planet. If only we had lots of recorded transit for some planet…

7. HD 209458 b … was the first transiting extrasolar planet discovered. Lots of people have looked at this system with Hubble, and their images becomes public a year after they’re taken.

8. How to Detect a Terrestrial Planet (with current technology!) Grab all the public HST images of HD 209458. Construct light curves for loads and loads of transits. See if the transits are regular like clockwork, or if their timing is a bit off.

9. What You’ll Do Retrieve and work with Hubble Space Telescope images! Learn about “Hot Jupiters”! See what “Limb Darkening” is all about! Learn about “Orbital Resonances”! See Eric get super excited and scribble on his chalk board!