HD 155876
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Hercules |
| Right ascension | 17h 12m 07.9117s |
| Declination | +45° 39′ 57.216″ |
| Apparent magnitude (V) | 9.52 |
| Characteristics | |
| A | |
| Evolutionary stage | main sequence |
| Spectral type | M3 |
| B | |
| Evolutionary stage | main sequence |
| Spectral type | M4 |
| Astrometry | |
| Radial velocity (Rv) | −30.9±0.5 km/s |
| Proper motion (μ) | RA: +348.59±5.68 mas/yr Dec.: −1624.84±6.80 mas/yr |
| Parallax (π) | 156.66±1.37 mas |
| Distance | 20.8 ± 0.2 ly (6.38 ± 0.06 pc) |
| Absolute magnitude (MV) | +10.31 |
| Orbit | |
| Period (P) | 12.9512±0.0096 yr |
| Semi-major axis (a) | 0.7620±0.0015″ |
| Eccentricity (e) | 0.7430±0.008 |
| Inclination (i) | 149.14±0.25° |
| Longitude of the node (Ω) | 160.0±1.3° |
| Periastron epoch (T) | 1991.032±0.011 |
| Argument of periastron (ω) (secondary) | 99.0±1.0° |
| Details | |
| A | |
| Mass | 0.379±0.035 M☉ |
| Radius | 0.37±0.07 R☉ |
| Luminosity | 0.018 L☉ |
| Temperature | 3,422±100 K |
| Metallicity [Fe/H] | −0.31±0.17 dex |
| B | |
| Mass | 0.369±0.035 M☉ |
| Radius | 0.37±0.07 R☉ |
| Temperature | 3,422±100 K |
| Metallicity [Fe/H] | −0.31±0.17 dex |
| Other designations | |
| BD+45°2505, GJ 661, HD 155876, HIP 84140, WDS J17121+4540, KUI 79, Furuhjelm 46 | |
| A: LFT 1326, LHS 433, LTT 15095, NLTT 44362 | |
| B: LFT 1327, LHS 434, LTT 15096, NLTT 44363 | |
| Database references | |
| SIMBAD | The system |
| A | |
| B | |
HD 155876, also known as Gliese 661, is a nearby binary star system, consisting of two very similar red dwarfs, located in the constellation Hercules.
The star's duplicity was discovered by the Dutch astronomer Gerard Kuiper in 1934 in a systematic survey for duplicity of the known stars within about 25 parsecs from the Sun, carried out with the 36-inch telescope of the Lick Observatory. HD 155876 is the nearest "true" (i. e. not brown dwarf) star system in Hercules, however, there is brown dwarf in this constellation, located closer: WISE 1741+2553.