67 Ophiuchi
67 Ophiuchi (67 Oph) is a class B5 Ib (blue supergiant) star in the constellation Ophiuchus. Its apparent magnitude is 3.93 and it is approximately 1200 light years away based on parallax. It is considered to be a member of the open cluster Collinder 359 (Melotte 186).
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Ophiuchus |
| Right ascension | 18h 00m 38.71619s |
| Declination | 2° 55′ 53.6324″ |
| Apparent magnitude (V) | 3.93 |
| Characteristics | |
| Spectral type | B5Ib |
| U−B color index | -0.62 |
| B−V color index | +0.03 |
| Astrometry | |
| Radial velocity (Rv) | -5.20 km/s |
| Proper motion (μ) | RA: +1.15 mas/yr Dec.: -9.35 mas/yr |
| Parallax (π) | 2.65 ± 0.54 mas |
| Distance | approx. 1,200 ly (approx. 380 pc) |
| Absolute magnitude (MV) | -3.50 |
| Details | |
| Mass | 8.4 M☉ |
| Luminosity | 2364 L☉ |
| Surface gravity (log g) | 3.03 cgs |
| Temperature | 15,420 K |
| Metallicity [Fe/H] | -0.01 dex |
| Rotational velocity (v sin i) | 40 km/s |
| Other designations | |
| Database references | |
| SIMBAD | data |
67 Oph has four companions. The closest is a magnitude 13.7 B1 main sequence star at 8.29", designated B. Component C (BD+02°3459) is the brightest close companion, a magnitude 8.1 B2 main sequence star at 54.32". Component D is a magnitude 12.5 star 8.37" from component C. Component E is a magnitude 10.9 star 46.53" from 67 Oph A.
This star was once considered part of the obsolete constellation Taurus Poniatovii, but after the International Astronomical Union officially recognized constellations, it was placed in Ophiuchus.