HD 149026 b

HD 149026 b is the name of an exoplanet in the constellation Hercules. The gas planet belongs to the class of hot Jupiter, but has only about the size of the planet Saturn. Its mass is about 70 - to 90 - times the mass of Earth and it orbits the approximately 260 light-years distant star HD 149026 Since his distance from this is very low, he needs for a round just three Earth days..

Surface temperature

On its side facing the sun, it has a temperature of 2000 degrees Celsius estimated. HD 149026 b is thus one of the hottest exoplanets known, and even hotter than some low-mass star.

The cause of this has never been observed in planetary heating is by assumptions of the scientists who discovered the phenomenon may be that HD reflects 149026 b almost no starlight, but converts the light energy to hitherto unexplained manner almost completely in infrared radiation (heat radiation) and directly radiates again. On its surface, the heat does not seem to spread by winds, the night side would therefore be much colder. From this heat capacities is concluded that it is also the smallest and densest known planet ( blacker than coal) with the darkest known surface.

According to another theory previously unknown processes play in the planet's atmosphere play an important role, there might be a connection with gaseous titanium or vanadium compounds found in higher concentrations in this. HD 149026 b contains more heavy elements than our entire solar system except the sun itself also the existence of a heat source inside the planet is contemplated.

The temperature was calculated from measured data of the infrared telescope Spitzer satellite by a team from the University of Central Florida in Orlando to the astronomer Joseph Harrington. Since the orbit of the exoplanet seen from Earth, so is that he disappears behind its star and regularly appears (see planetary transit), could be estimated from the measured differences in the brightness temperature. The result was published in the May 2007 issue of the scientific journal Nature.

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