  | |
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Ophiuchus |
| Right ascension | 18h 07m 18.35888s[1] |
| Declination | +08° 44′ 01.9181″[1] |
| Apparent magnitude (V) | 4.64[2] |
| Characteristics | |
| Spectral type | G8III[3] |
| U−Bcolor index | +0.73[4] |
| B−Vcolor index | +0.97[4] |
| Astrometry | |
| Radial velocity (Rv) | −3.00±0.09[5] km/s |
| Proper motion (μ) | RA: +9.857[1]mas/yr Dec.: +29.770[1]mas/yr |
| Parallax (π) | 13.1352±0.1891 mas[1] |
| Distance | 248 ± 4 ly (76 ± 1 pc) |
| Absolute magnitude (MV) | 0.03[2] |
| Details[6] | |
| Mass | 2.87±0.09 M☉ |
| Radius | 12.55+0.27 −0.34[1] R☉ |
| Luminosity | 88.8±1.5[1] L☉ |
| Surface gravity (log g) | 3.00±0.02 cgs |
| Temperature | 5,001+70 −52[1] K |
| Metallicity [Fe/H] | 0.10±0.01 dex |
| Rotational velocity (v sin i) | 0.32±0.45 km/s |
| Age | 400±30 Myr |
| Other designations | |
| 71 Oph,BD+08°3582,GC 24693,HD 165760,HIP 88765,HR 6770,SAO 123140[7] | |
| Database references | |
| SIMBAD | data |
71 Ophiuchi is a single[8]star in theequatorialconstellation ofOphiuchus. It is visible to the naked eye as a faint, yellow-hued point of light with anapparent visual magnitude of 4.64.[2] The star is located approximately 273 light years away from the Sun based onparallax,[9] and is moving closer with aradial velocity of −3 km/s.[5]
At the estimated age of 400 million years,[6] this is an aginggiant star with astellar classification of G8III,[3] having exhausted the supply of hydrogen at itscore and expanded to around 13[1] times theSun's radius. It is ared clump giant,[10] which means it is on thehorizontal branch and is generating energy throughhelium fusion at its core. The star has 2.9 times themass of the Sun and is radiating 89 times theSun's luminosity from its swollenphotosphere at aneffective temperature of 5,001 K.[6]
