HR 6902
Star system in the constellation Ophiuchus
From Wikipedia, the free encyclopedia
HR 6902 (also designated V2291 Oph) is a binary system located 880 light years away from the Sun in the Ophiuchus constellation. The system includes an orange bright giant star and a B-type main sequence star, forming an eclipsing binary of Zeta Aurigae type. The system is also surrounded by a warm circumstellar envelope and the spectra show silicon and carbon absorption up to a distance of 3.3 giant radii.[4]
Visible, blue and ultraviolet light curves for an eclipse of V2291 Ophiuchi, adapted from Griffin et al. (1995)[1] | |
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Ophiuchus |
| Right ascension | 18h 25m 38.799s[2] |
| Declination | +08° 01′ 55.23″[2] |
| Apparent magnitude (V) | +5.64[3] |
| Characteristics | |
| Spectral type | G9IIb / B8V |
| Variable type | Zeta Aurigae-type |
| Astrometry | |
| Proper motion (μ) | RA: −3.920[2] mas/yr Dec.: −6.549[2] mas/yr |
| Parallax (π) | 3.7061±0.1604 mas[2] |
| Distance | 880 ± 40 ly (270 ± 10 pc) |
| Absolute magnitude (MV) | –1.33[3] |
| Orbit | |
| Period (P) | 1.055[4] yr |
| Semi-major axis (a) | 1.96[4] AU |
| Eccentricity (e) | 0.311[4] |
| Inclination (i) | 87[4]° |
| Details | |
| Mass | 3.86/2.95[4] M☉ |
| Radius | 33/3[4] R☉ |
| Luminosity | 562/146 L☉ |
| Temperature | 4,900/11,600[4] K |
| Other designations | |
| V2291 Oph, GSC 01023-02454, HD 169690, HD 169689, 2MASS J18253880+0801551, BD+07 3682, FK5 1478, PPM 165790, HIP 90313, SAO 123462 | |
| Database references | |
| SIMBAD | data |