WASP-17 b
Description: WASP-17b, officially named Ditsö̀, is an exoplanet in the constellation Scorpius that is orbiting the star WASP-17. Its discovery was announced on 11 August 2009. It is the first planet discovered to have a retrograde orbit, meaning it orbits in a direction counter to the rotation of its host star. This discovery challenged traditional planetary formation theory. In terms of diameter, WASP-17b is one of the largest exoplanets discovered and at half Jupiter's mass, this made it the most puffy planet known in 2010. On 3 December 2013, scientists working with the Hubble Space Telescope reported detecting water in the exoplanet's atmosphere.
Physical Properties
Mass (Jupiter mass): 0.78 MJ
Radius (Jupiter radius): 1.87 RJ
Density: 0.082 g/cm³
Equilibrium Temperature: 1755.0 K
Orbital Parameters
Orbital Period: 3.73543 days
Semi-major Axis: 0.0515 AU
Eccentricity: Unknown
Inclination: 86.63°
Host Star Properties
Host Star: WASP-17
Spectral Type: F4
Temperature: 6550.0 K
Stellar Mass: 2.28 M☉
Stellar Radius: 1.49 R☉
Discovery Information
Planet Letter: b
Object ID: 3.11446
Host ID: 2.103455
Discovery Date: 2010-01
Discovery Year: 2009
Discovery Method: Transit
Discovery Locale: Ground
Discovery Facility: SuperWASP
Discovery Instrument: iKon-L CCD Camera