HD 142022

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**HD 142022**
Observation data Epoch J2000.0
Constellation (pronunciation)	Octans
Right ascension	16h 10m 15.0238s
Declination	−84º 13' 53.8025″
Apparent magnitude (V)	7.69
Absolute magnitude (V)	4.91
Distance	117 ly (35.9 pc)
Spectral type	G9V
Other designations
CD−83 202, Gl 606.1, GJ 9536, HIP 79242, SAO 258738

HD 142022 is a binary star system located in the southernmost constellation Octans located at a distance of 117 ly. The primary star (HD 142022 A) has a spectral type of G9V and has apparent magnitude of 7.69. Its mass is 1% less than the Sun but the radius is only 70.5%. The star’s age is old, only 400 million years younger than the Universe itself. It is a Population I star with metallicity of 55% greater than solar.

The primary star has a single planetary system as of 2005.

[edit] HD 142022 Ab

**HD 142022 Ab**
Orbital elements
Extrasolar planet		List of extrasolar planets
Semimajor axis	(a)	2.93 AU
Eccentricity	(e)	0.53±0.20
Orbital period	(P)	1928±46 d
Angular distance	(θ)	81.6 mas
Longitude of periastron	(ω)	170±9°
Time of periastron	(T₀)	2,450,971±75 JD
Semi-amplitude	(K)	92±65 m/s
Physical characteristics
Mass	(m)	>4.47 M_J
Discovery information
Discovery date		2005
Discoverer(s)		Eggenberger et al.
Detection method		Radial Velocity
Discovery status		Published

The radial velocity method by Eggenberger et al. 2005 found that HD 142022 A is wobbling which indicated the presence of a massive planet, designating as HD 142022 Ab, with mass of 4.5 times Jupiter. It has a relatively wide separation between a planet and a star with nearly 3 AU (angular separation of 81.6 mas as viewed from Earth), which takes 1928 days or 5.28 years to revolve. As it is typical for long-period planets, it has a relatively high eccentricity of 53±20%.