1. Finding the Radius of Exoplanet CoRoT-2b By Kevin Ji Cluster 4

2. What is an Exoplanet? A planet that orbits around a star that is not our sun More than one per star

3. Recent Exoplanet Discoveries First mission dedicated to finding exoplanets: CoRoT in 2006 Kepler by NASA sent to discover exoplanets in 2009 and has found over 1000 Recently, found Kepler 452b to be “Earth’s cousin” with a similar mass, radius, and parent star

4. CoRoT-2b Hot Jupiter 2 nd exoplanet discovered by CoRoT in 2007 G star, like our sun 800 light years away

5. How did we detect this planet Called the Transit Method Planet passes between us and the star, blocks some of the light Transit time and change in apparent brightness can be measured looking at the light curve With this and the mass of the parent star and orbital radius, figure out the radius of the planet Must be edge on

6. What is a Light Curve A graph showing the changes in brightness of a star over a period of time

7. Transit Method in Depth Looking at the light curve, the width of the dip is the time it took the planet to go in front of the sun, t Depth of the dip is change in brightness due to planet, and convert this to flux, % Given orbital radius, a, and orbital period, p Find star radius Find planet radius

8. CoRot-2b P=41.8 hours a = 0.0281 AU Star Mass = 0.97 Sun Mass T= 2.09 hours %=0.0273 Radius Calculated: 1.56 Jupiter Radii Actual Radius: 1.43 Jupiter Radii

10. What happens if the radius of the planet is larger Planet is larger, covers more of the sun’s light Causes difference in light during transit period to be larger and deeper eclipse depth

12. What happens when the star’s mass is larger Larger radius of star, more distance for planet to cross Planet covers less of the sun’s light, less percent light blocked

14. Work Cited "Astrophysics Group." » Exoplanet UK Community Meeting – Cambridge, April 14-16 2014. Web. 29 July 2015. Bisque, Matthew L. CCDSoft. Vers. 5.00.216. Computer software. Software Bisque, 2013. Windows 7, 99.2 MB, download. "Exoplanet - Amateur Detection." Exoplanet - Amateur Detection. Web. 30 July 2015. Joye, William. SAOImage DS9. Vers.6.1.2. Computer software. Future Directions for Astronomical Image Display. 2013. Windows 7, 10.5 MB, download. KeirMierle. PyLab. Vers. 2.7.2. Computer software. SciPy.org, 2013. Python, 54.7 MB, download. "Planet." - Wikipedia. Web. 29 July 2015.. "Planet Hunters." Planet Hunters. Web. 29 July 2015. "Planeta Gêmeo Da Terra Pode Ser Descoberto Em 2013." - Mega Curioso. Web. 29 July 2015. Python. Vers. 2.7.2 Computer software. Python Software Foundation, 2013. Windows 7, 20.7 MB, download. "Transit Simulator - Extrasolar Planets - NAAP." Transit Simulator - Extrasolar Planets - NAAP. Web. 29 July 2015. "Transit Simulator - Extrasolar Planets - NAAP." Transit Simulator - Extrasolar Planets - NAAP. Web. 29 July 2015.