Discovery[1][2] | |
---|---|
Discovered by | California and Carnegie Planet Search |
Discovery site | W. M. Keck Observatory |
Discovery date | November 1, 1999 |
Doppler spectroscopy | |
Orbital characteristics[3] | |
2.051+0.079 −0.087 AU | |
Eccentricity | 0.104+0.009 −0.008 |
2.944 ± 0.002 years (1,075.30 ± 0.73 d) | |
Inclination | 86.116°+19.957° −20.530° |
38.852°+15.084° −21.589° | |
2,449,333.898+14.739 −15.380 | |
112.816°+5.254° −5.448° | |
Semi-amplitude | 114.583+1.067 −1.196 m/s |
Star | 109 Piscium |
Physical characteristics[3] | |
Mass | 5.743+1.011 −0.289 MJ |
109 Piscium b (aka HD 10697 b) is a long-period extrasolar planet discovered in orbit around 109 Piscium. It is about 5.74 times the mass of Jupiter and is likely to be a gas giant. As is common 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 to 20 K warmer because of internal heating.[2] It orbits within the habitable zone.[1]
Preliminary astrometric measurements suggested that the orbital inclination is 170.3°,[4] 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.[5] A more plausible suggestion is that this planet shares its star's inclination, of 69+21
−26°.[6][7] In 2022, the inclination and true mass of 109 Piscium b were measured via astrometry. The inclination estimate is consistent with that of the stellar rotation.[3]