HD 16175

HD 16175 is a 7th magnitude G-type star with temperature about 6,000 K located 196 light-years (60 parsecs) away^[2] in the Andromeda constellation. This star is only visible through binoculars or better equipment; it is also 3.3 times more luminous, is 1.34 times more massive, and has a radius 1.66 times bigger than our local star.^[6]

HD 16175 / Buna

Observation data Epoch J2000.0      Equinox J2000.0
Constellation	Andromeda[1]
Right ascension	02h 37m 01.91118s[2]
Declination	+42° 03′ 45.4685″[2]
Apparent magnitude (V)	7.28[3]
Characteristics
Evolutionary stage	subgiant[2]
Spectral type	F8 IV[4]
B−V color index	0.64[3]
Astrometry
Radial velocity (Rv)	21.83±0.14[2] km/s
Proper motion (μ)	RA: −38.864 mas/yr[2] Dec.: −41.234 mas/yr[2]
Parallax (π)	16.6670±0.0279 mas[2]
Distance	195.7 ± 0.3 ly (60.0 ± 0.1 pc)
Absolute magnitude (MV)	3.40[5]
Details
Mass	1.34±0.01[6] M☉
Radius	1.66±0.04[6] R☉
Luminosity	3.3±0.01[6] L☉
Surface gravity (log g)	4.12±0.03[6] cgs
Temperature	6,048±35[6] K
Age	3.2±0.2[6] Gyr
Other designations
BD+41°496, HIP 12191, SAO 38170
Database references
SIMBAD	data

The star HD 16175 is named Buna. The name was selected in the NameExoWorlds campaign by Ethiopia, during the 100th anniversary of the IAU. Buna is the commonly used word for coffee in Ethiopia.^[7][8]

Planetary system

The discovery of the exoplanet HD 16175 b was published in the June 2009 issue of the Publications of the Astronomical Society of the Pacific.^[5] The planetary parameters were updated in 2016.^[9] In 2023, the inclination and true mass of HD 16175 b were determined via astrometry.^[10]

The HD 16175 planetary system^[10]

Companion (in order from star)	Mass	Semimajor axis (AU)	Orbital period (years)	Eccentricity	Inclination	Radius
b / Abol	5.9+1.8 −1.0 MJ	2.13+0.075 −0.08	2.686+0.031 −0.039	0.675±0.026	59+20 −19 or 121+19 −20°	—

See also

• HD 96167
• List of extrasolar planets