HD 43197 b

HD 43197 b / Equiano
Discovery
Discovered byNaef et al.
Discovery siteLa Silla Observatory
Discovery dateOctober 19, 2009
radial velocity (HARPS)
Orbital characteristics
0.882+0.035
−0.039
 AU
Eccentricity0.742+0.017
−0.018
308.9+2.3
−2.8
 d
2452535.102+17.503
−14.898
268.525°+3.824°
−4.523°
Semi-amplitude25.439+1.472
−1.121
 m/s
StarHD 43197
Physical characteristics
Mass≥0.553+0.052
−0.048
 MJ

    HD 43197 b is an extrasolar planet which orbits the G-type main sequence or subgiant star HD 43197, located approximately 204 light years away in the constellation Canis Major. This planet has a minimum mass 55% that of Jupiter and takes 0.85 years to orbit the star at a semimajor axis of 0.882 AU. It has a high eccentricity of 0.74, but its inclination is not known. This planet was detected by HARPS on October 19, 2009, together with 29 other planets.

    In 2022, a second super-Jovian planet was discovered orbiting HD 43197 using a combination of radial velocity and astrometry. Assuming HD 43197 b shares the outer planet's orbital inclination, its true mass would be about 4 MJ.

    The planet HD 43197 b is named Equiano. The name was selected in the NameExoWorlds campaign by Nigeria, during the 100th anniversary of the IAU. Olaudah Equiano was a writer and abolitionist from Ihiala, Nigeria who fought injustice and for the elimination of the slave trade.