Planets with Two Suns

I don’t watch Star Wars as much as you all do but I do know that Luke Skywalker and Anakin Skywalker’s home planet is Tatooine, a planet in a binary stars system.  I wondered how it feels like to live on a planet with two sunrises and sunsets. It would be awesome to live on a planet like that. Tatooine is just a fictional planet and we can never find Tatooine. Well, we might not see Tatooine but astronomers already discovered a few Tatooine-like planets, planets that have two suns. These planets are called circumbinary planets.

In September 2011, Kepler has discovered and confirmed the first existence of such planets. The planet, called Kepler-16b is only 200 light years from Earth, not a far distance. Unlike Tatooine, the planet is mostly gaseous and not suitable to support life. However, this planet confirm that there is a possibility that a planet can exist in a binary system and given that most stars in the universe is in a binary system, this discover significantly higher the chance of finding a planet that can support life.

Planet Kepler-16b was discovered by studying the transit of the system. They discovered that besides the dips in brightness from primary and secondary eclipses, there was also another dip while the stars were not eclipsing each other. This event hinted that there must a third body in the system. The third body cannot be another star because the gravitational effect is not great that the body must be low mass. Planet Kepler-16b was discovered to be orbiting both stars. Further study confirmed that the planet is about the size of Saturn. Both stars are smaller than our Sun and the planet orbital period is about 225 days.

 Recently, there were two circumbinary planets were discovered. The second planet that is Tatooine-like is call Kepler-34b which has 22% mass and 76%width of Jupiter. The planet is 4900 light years from us and orbit around two sunlike stars. The third planet is called Kepler-35b, about 13% mass and 73% width of Jupiter and about 5400 light years from us.

Astronomer estimated that there are about 1% of binary system can have circumbinary planet orbiting around them, a huge number because there are a lot of binary system out there.

Sources:

http://www.msnbc.msn.com/id/45960242/ns/technology_and_science-space/t/two-new-tatooine- planets-two-suns-discovered/#.T2P7e2JSSg2

http://science.nasa.gov/science-news/science-at-nasa/2011/15sep_doublesuns/

http://www.huffingtonpost.com/2012/01/12/real-life-tatooine-planet_n_1201827.html