HD 120084

HD 120084 is a star with an orbiting exoplanet^[3] in the northern constellation of Ursa Minor. With an apparent magnitude of 5.91,^[3] it is just visible to the naked eye in suburban skies.^[7] The distance to this system is 339 light-years based on parallax measurements, but it is drifting closer to the Sun with a radial velocity of −9 km/s.^[2]

ConstellationUrsa Minor^[1]

Right ascension13^h 42^m 39.20162^s[2]

Declination+78° 03′ 51.9800″^[2]

Apparentmagnitude(V)5.91^[3]

Quick facts Constellation, Right ascension ...

HD 120084

Location of HD 120084 (circled in red)
Observation data Epoch J2000.0      Equinox ICRS
Constellation	Ursa Minor[1]
Right ascension	13h 42m 39.20162s[2]
Declination	+78° 03′ 51.9800″[2]
Apparent magnitude (V)	5.91[3]
Characteristics
Evolutionary stage	Red clump[4]
Spectral type	G7III[3]
B−V color index	1.000[3]
Astrometry
Radial velocity (Rv)	−8.97±0.13[2] km/s
Proper motion (μ)	RA: −64.900(31) mas/yr[2] Dec.: 46.164(33) mas/yr[2]
Parallax (π)	9.6277±0.0258 mas[2]
Distance	338.8 ± 0.9 ly (103.9 ± 0.3 pc)
Absolute magnitude (MV)	+0.96[3]
Details
Mass	2.661±0.335[4] M☉
Radius	11.03±0.65[4] R☉
Luminosity	63+8 −7[4] L☉
Surface gravity (log g)	2.779±0.075[4] cgs
Temperature	4,969±40[5] K
Metallicity [Fe/H]	0.12±0.03[5] dex
Rotational velocity (v sin i)	2.44[3] km/s
Other designations
BD+78°466, FK5 3090, HIP 66903, SAO 7876[6]
Database references
SIMBAD	data
Exoplanet Archive	data

Close

The spectrum of this star matches a type of G7III, indicating it is a G-type giant, an evolved star that used up its hydrogen fuel and has expanded.^[3] After undergoing a helium flash, it is now in the red clump stage generating energy through the fusion of helium.^[4] It has 2.7 times the mass of the Sun and a radius about 11 times the radius of the Sun. It radiates 60 times the Sun's luminosity from its photosphere at an effective temperature of around 4,969 K.^[3][5]