Discovery date November 14, 1999 Discovery site Keck Observatory | Discoverer(s) Vogt et al. Discovery status Published | |
109 Piscium b (aka HD 10697 b) is a long-period extrasolar planet discovered in orbit around 109 Piscium. It is at least 6.38 times the mass of Jupiter and is likely to be a gas giant. As typical for long-period planets discovered around other stars, it has an orbital eccentricity greater than that of Jupiter.
The discoverers estimate its effective temperature as 264 K from solar heating, but it could be at least 10-20 K warmer because of internal heating.
Preliminary astrometric measurements suggested that the orbital inclination is 170.3°, yielding an object mass of 38 times that of Jupiter, which would make it a brown dwarf. However, subsequent analysis indicates that the precision of the measurements used to derive the astrometric orbit is insufficient to constrain the parameters, so the true inclination and mass remain unknown.
A more plausible suggestion is that this planet shares its star's inclination, of 69+21
−26°.