A new type of planet

To pick up from yesterday, what was the planet that was discovered?

As it's sometimes said, one instance is an anomaly, two might be coincidence and three is a pattern. The planet that was discovered by the HATnet, HAT-P-1, was the second of the type of planet that has been termed the puffy planet, a type of gas giant. A third was discovered in 2007.

Puffy planets are huge. They are larger than even Jupiter. But surprisingly, they are less dense than even Saturn, which is often said famously to be able to float in a bathtub. To quote Bakos in the official press release, ""This planet is about one-quarter the density of water. In other words, it's lighter than a giant ball of cork!"

The mystery involved with these planets, now, is to discover exactly how they are formed. Within current astronomical theories, there is no explanation for them. There is yet another mystery, as well: they are what is often term as "hot Jupiters", or very hot gas giants. How they have remained so large and hot--given they are not by any means young planets--remains puzzling.

Tomorrow, the methodology used to determine the characteristics of the puffy planets, or, "how can they tell how dense something so far away is, anyway?"

Citations:

Chang, Kenneth. (2006). Puzzling puffy planet, less dense than cork, is discovered. Retrieved February 5 2009, from: http://www.nytimes.com/2006/09/15/science/space/15planet.html?ex=1315972800&en=3646d4e6a10ec036&ei=5089&emc=rss

European Space Agency. (2007). COROT discovers its first exoplanet and catches scientists by surprise. Retrieved February 5 2009, from: http://www.esa.int/esaCP/SEMCKNU681F_index_0.html

Harvard-Smithsonian Center for Astrophysics. (2006) Strange new planet baffles astronomers. Retrieved February 5 2009, from: http://www.cfa.harvard.edu/press/2006/pr200624.html