HD 81040 b

HD 81040 b is a massive gas giant exoplanet that orbits the star HD 81040, discovered in 2005 by radial velocity.^[2] Its orbital period is just over 1000 days. It has a semimajor axis of about 1.95 AU, and its orbit is quite eccentric, at a little over 0.5.^[3][4]

HD 81040 b

Radial velocity curve of HD 81040 b[1]
Discovery
Discovered by	Sozzetti et al.[2]
Discovery site	Observatoire de Haute-Provence in France
Discovery date	November 24, 2005
Detection method	Doppler Spectroscopy
Orbital characteristics
Semi-major axis	1.946 ± 0.014 AU (291,100,000 ± 2,100,000 km)[3]
Eccentricity	0.525+0.024 −0.026[3]
Orbital period (sidereal)	1,004.7 ± 3.0 days (2.7507 ± 0.0082 years)[4]
Inclination	111.4°+4.4° −4.7°[4]
Longitude of ascending node	19.2°+5.0° −4.8°[4]
Time of periastron	245511.1+10 −8.7[3]
Argument of periastron	73.1°±4.3°[4]
Semi-amplitude	168 ± 9[2]
Star	HD 81040
Physical characteristics
Mass	7.53±0.032 MJ[4]

Astrometry of HD 81040 using Gaia, published in several papers, has determined an orbital inclination of about 111°. This, combined with the minimum mass, gives a true mass of 7.53 M_J.^{[3][1][5][6][4]} Since the inclination is high, there is a small chance that the planet transits.^[3]

Astrometric orbit of HD 81040 b^[1]

See also

• HD 33564 b