HD 169830

HD 169830 is a star in the southern constellation of Sagittarius. It has a yellow-white hue and is dimly visible to the naked eye with an apparent visual magnitude of +5.90.^[2] The star is located at a distance of 120 light years from the Sun based on parallax. It is drifting closer with a radial velocity of −17.3 km/s,^[4] and is predicted to come as close as 20.7 ly (6.4 pc) in 2.08 million years.^[10] HD 169830 is known to be orbited by two large Jupiter-like exoplanets.

HD 169830

Observation data Epoch J2000.0      Equinox J2000.0
Constellation	Sagittarius
Right ascension	18h 27m 49.48500s[1]
Declination	–29° 49′ 00.7008″[1]
Apparent magnitude (V)	+5.90[2]
Characteristics
Spectral type	F7V[3]
B−V color index	0.517±0.004[2]
Variable type	“None”
Astrometry
Radial velocity (Rv)	−17.271±0.0004[4] km/s
Proper motion (μ)	RA: −0.341[1] mas/yr Dec.: 16.103[1] mas/yr
Parallax (π)	27.1461±0.1469 mas[1]
Distance	120.1 ± 0.7 ly (36.8 ± 0.2 pc)
Absolute magnitude (MV)	+3.08[2]
Details[5]
Mass	1.4 M☉
Radius	1.84 R☉
Luminosity	4.63[6] L☉
Surface gravity (log g)	4.06 cgs
Temperature	6,300±50[6] K
Metallicity [Fe/H]	0.15 dex
Rotation	8.3 d[7]
Rotational velocity (v sin i)	3.83 km/s
Age	4.95[8] Gyr
Other designations
CD−29°14965, Gaia DR2 4048037707717866880, GC 25175, HD 169830, HIP 90485, HR 6907, SAO 186838, GSC 06869-01277, 2MASS J18274949-2949007[9]
Database references
SIMBAD	data
ARICNS	data

This is an F-type main-sequence star^[6] with a stellar classification of F7V.^[3] It is 3.83^[8] billion years old and chromospherically inactive^[8] with a slow rotation rate,^[8] having a projected rotational velocity of 3.83 km/s.^[5] This star is 40% more massive and 84% larger than the Sun. Combining the mass and radius makes the surface gravity only 41% that of the Sun. It is radiating 4.6^[6] times the luminosity of the Sun from its photosphere at an effective temperature of 6,300 K.^[6]

A candidate stellar companion, designated component B, lies at an angular separation of 11″ along a position angle of 265°.^[11]

Planetary system

On April 15, 2000, the Geneva Extrasolar Planet Search Team announced the discovery of a minimum mass 3 M_J planet in a 226-day orbit.^[12][6] Three years later on June 30, 2003, the same team, using the same method, discovered a minimum mass 3.5 M_J second planet orbiting the star.^[7] In 2022, the inclination and true mass of HD 169830 c were measured via astrometry.^[13]

The HD 169830 planetary system^[14][13]

Companion (in order from star)	Mass	Semimajor axis (AU)	Orbital period (days)	Eccentricity	Inclination	Radius
b	≥2.956+0.070 −0.069 MJ	0.8130+0.0083 −0.0084	225.789+0.074 −0.081	0.306+0.012 −0.013	—	—
c	7.669+1.937 −2.755 MJ	3.075+0.132 −0.146	1818.8+5.7 −6.4	0.246+0.022 −0.018	24.469+12.739 −7.205°	—

See also

• HD 69830
• List of extrasolar planets