HD 120084
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Ursa Minor |
| Right ascension | 13h 42m 39.20162s |
| Declination | +78° 03′ 51.9800″ |
| Apparent magnitude (V) | 5.91 |
| Characteristics | |
| Evolutionary stage | Red clump |
| Spectral type | G7III |
| B−V color index | 1.000 |
| Astrometry | |
| Radial velocity (Rv) | −8.97±0.13 km/s |
| Proper motion (μ) | RA: −64.900(31) mas/yr Dec.: 46.164(33) mas/yr |
| Parallax (π) | 9.6277±0.0258 mas |
| Distance | 338.8 ± 0.9 ly (103.9 ± 0.3 pc) |
| Absolute magnitude (MV) | +0.96 |
| Details | |
| Mass | 2.661±0.335 M☉ |
| Radius | 11.03±0.65 R☉ |
| Luminosity | 63+8 −7 L☉ |
| Surface gravity (log g) | 2.779±0.075 cgs |
| Temperature | 4,969±40 K |
| Metallicity [Fe/H] | 0.12±0.03 dex |
| Rotational velocity (v sin i) | 2.44 km/s |
| Other designations | |
| BD+78°466, FK5 3090, HIP 66903, SAO 7876 | |
| Database references | |
| SIMBAD | data |
| Exoplanet Archive | data |
HD 120084 is a star with an orbiting exoplanet in the northern constellation of Ursa Minor. With an apparent magnitude of 5.91, it is just visible to the naked eye in suburban skies. 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.
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. After undergoing a helium flash, it is now in the red clump stage generating energy through the fusion of helium. 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.