HAT-P-11b

HAT-P-11b (or Kepler-3b) is an extrasolar planet orbiting the star HAT-P-11. This planet was discovered by the transit method and submitted for publication on 2 January 2009.
This planet is located approximately away in the constellation of Cygnus, orbiting the 10th magnitude K-type star HAT-P-11. This planet was the smallest transiting planet known when first discovered, with a radius about 5 times that of Earth; but is more massive than Gliese 436 b at a true mass of 26 times that of Earth. This planet orbits about the same distance from the star as 51 Pegasi b is from 51 Pegasi, typical of transiting planets. However, the orbit of this planet is eccentric, at around 0.198, unusually high for hot Neptunes. HAT-P-11b's orbit is also highly inclined, with a tilt of approximately 103 degrees relative to its star's rotation.
The HAT-P-11 system was within the field of view of the Kepler spacecraft.
Its radial velocity is drifting and this may be a result of an as-yet-undiscovered planet in the system.
The planet fits models for 90% heavy elements. Expected temperature is 878 ± 15K.
Actual temperature must await calculations of secondary transit.
On 24 September 2014, NASA reported that HAT-P-11b is the first Neptune-sized exoplanet known to have a relatively cloud-free atmosphere and, as well, the first time molecules, namely water vapor, of any kind have been found on such a relatively small exoplanet.
==See also==
* Gliese 436 b
* HATNet Project
* HAT-P-7b
* Kepler Mission
==References==
==External links==
* 
Category:Exoplanets
Category:Exoplanets discovered in 2009
Category:Gas giants
Category:Transiting exoplanets
Category:Cygnus (constellation)
Category:Hot Neptunes
Category:Exoplanets discovered by Kepler (spacecraft)