WASP-17b
Artist impression of Ditsö̀ | |
| Discovery | |
|---|---|
| Discovered by | David R. Anderson et al |
| Discovery date | 11 August 2009 |
| Transit (including secondary eclipse) | |
| Orbital characteristics | |
| 0.05151±0.00035 AU | |
| Eccentricity | <0.020 |
| 3.7354845±0.0000019 d | |
| Inclination | 86.83°+0.68° −0.53° |
| −70 | |
| Semi-amplitude | 56.0+4.1 −4.0 m/s |
| Star | WASP-17 |
| Physical characteristics | |
| 1.991±0.081 RJ | |
| Mass | 0.512±0.037 MJ |
Mean density | 0.080+0.013 −0.011 g/cm3 |
| Temperature | 1,550+170 −200 K |
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.
WASP-17b's name was selected in the NameExoWorlds campaign by Costa Rica, during the 100th anniversary of the International Astronomical Union. Ditsö̀ is the name that the god Sibö̀ gave to the first Bribri people in Talamancan mythology.