Hercules Constellation Hosts The Hottest Planet Known

Astronomers have located the hottest planet yet: its atmospheric temperatures measure about 3,700 degrees Fahrenheit -- almost twice that of the previously known hottest planet. Yikes!

For HD 149026 b to reach such blistering heat, researchers say, it must suck up nearly all the energy it receives from its big bluish star. If so, the gaseous planet could be nearly pitch-black in color. Experts cannot fully explain the planet's intense heat, but they speculate that it may have something to do with its unusually high concentration of heavy elements.

"This is a weird planet, and this is yet another weird thing about it," says planetary scientist Joseph Harrington of the University of Central Florida in Orlando.

Harrington suggests that the planet -- located 279 light years away in the Hercules constellation -- may be blacker than coal, because the planet must have zero reflectivity (of light/energy from its sun) to reach those temperatures. Researchers plan to study the planet using additional infrared frequencies in an effort to determine the atmosphere's constituents.

NASA lists two of its other superlatives:

HD 149026b is located 279 light-years away in the constellation Hercules. It is the smallest and densest known transiting planet, with a size similar to
Saturn's and a core suspected to be 70 to 90 times the mass of Earth. It speeds around its star every 2.9 days.

This planet was analyzed using the Spitzer Space Telescope, which was also used to create the first map of an exosolar planet.

A Tale of Two Exoplanets: One Incredibly Hot, the Other Extremely Windy [Scientific American]