70 Ophiuchi
Location of 70 Ophiuchi in the constellation Ophiuchus | |
| Observation data Epoch J2000 Equinox | |
|---|---|
| Constellation | Ophiuchus |
| 70 Ophiuchi | |
| Right ascension | 18h 05m 27.285s |
| Declination | +02° 29′ 00.36″ |
| Apparent magnitude (V) | 4.00 - 4.03 |
| A | |
| Right ascension | 18h 05m 27.248s |
| Declination | +02° 30′ 00.53″ |
| Apparent magnitude (V) | 4.13 |
| B | |
| Right ascension | 18h 05m 27.463s |
| Declination | +02° 29′ 56.21″ |
| Apparent magnitude (V) | 6.07 |
| Characteristics | |
| Spectral type | K0V + K4V |
| Apparent magnitude (B) | 4.97/7.26 |
| Apparent magnitude (R) | 3.6/5.6 |
| U−B color index | +0.69 |
| B−V color index | +0.82/+1.15 |
| Variable type | BY Dra or RS CVn |
| Astrometry | |
| 70 Oph A | |
| Radial velocity (Rv) | −5.73±0.18 km/s |
| Proper motion (μ) | RA: 206.525 mas/yr Dec.: −1107.492 mas/yr |
| Parallax (π) | 195.5674±0.1964 mas |
| Distance | 16.68 ± 0.02 ly (5.113 ± 0.005 pc) |
| Absolute magnitude (MV) | +5.627 |
| 70 Oph B | |
| Radial velocity (Rv) | −9.47±0.22 km/s |
| Proper motion (μ) | RA: 333.292 mas/yr Dec.: −1068.354 mas/yr |
| Parallax (π) | 195.2166 ± 0.1012 mas |
| Distance | 16.707 ± 0.009 ly (5.123 ± 0.003 pc) |
| Absolute magnitude (MV) | +7.427 |
| Orbit | |
| Period (P) | 88.435±0.017 yr |
| Semi-major axis (a) | 4.526″±0.007″ (23.6±0.5 AU) |
| Eccentricity (e) | 0.5005±0.0006 |
| Inclination (i) | 121.1±0.1° |
| Longitude of the node (Ω) | 121.7±0.2° |
| Periastron epoch (T) | 45,809±14 |
| Argument of periastron (ω) (secondary) | 193.4±0.3° |
| Semi-amplitude (K1) (primary) | 3.51±0.04 km/s |
| Semi-amplitude (K2) (secondary) | 4.25±0.05 km/s |
| Details | |
| 70 Oph A | |
| Mass | 0.834±0.055 M☉ |
| Radius | 0.831±0.004 R☉ |
| Luminosity (bolometric) | 0.51±0.01 L☉ |
| Habitable zone inner limit | 0.623 AU |
| Habitable zone outer limit | 1.242 AU |
| Surface gravity (log g) | 4.5 cgs |
| Temperature | 5,282 K |
| Metallicity [Fe/H] | 0.04±0.05 dex |
| Rotation | 19.7 days |
| Age | 6.2±1.0 Gyr |
| 70 Oph B | |
| Mass | 0.782±0.064 M☉ |
| Radius | 0.670±0.009 R☉ |
| Luminosity (bolometric) | 0.15±0.02 L☉ |
| Habitable zone inner limit | 0.359 AU |
| Habitable zone outer limit | 0.712 AU |
| Temperature | 4,623 K |
| Metallicity [Fe/H] | 0.04±0.05 dex |
| Age | 6.2±1.0 Gyr |
| Other designations | |
| p Oph, 70 Oph, V2391 Oph, BD+02 3482, GJ 702, HD 165341, HIP 88601, HR 6752, SAO 123107, PLX 4137 | |
| 70 Oph A: LHS 458 | |
| 70 Oph B: LHS 459 | |
| Database references | |
| SIMBAD | The system |
| A | |
| B | |
| Exoplanet Archive | data |
| ARICNS | data |
70 Ophiuchi (p Ophiuchi) is a binary star system located 16.7 light-years away from the Earth. It is in the constellation Ophiuchus. At magnitude 4 it appears as a dim star visible to the unaided eye away from city lights.