36 Ophiuchi
Location of 36 Ophiuchi in the constellation Ophiuchus | |
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Ophiuchus |
| Right ascension | A: 17h 15m 20.851s B: 17h 15m 20.978s C: 17h 16m 13.3624s |
| Declination | A: −26° 36′ 09.04″ B: −26° 36′ 10.18″ C: −26° 32′ 46.129″ |
| Apparent magnitude (V) | 5.08/5.03/6.34 |
| Characteristics | |
| Spectral type | K2 V/K1 V/K5 V |
| U−B color index | 0.51(AB)/1.04 |
| B−V color index | 0.85(AB)/1.16 |
| Variable type | C: RS CVn |
| Astrometry | |
| 36 Oph A | |
| Radial velocity (Rv) | −0.6 km/s |
| Proper motion (μ) | RA: −498.600 mas/yr Dec.: −1,149.158 mas/yr |
| Parallax (π) | 168.0031±0.1343 mas |
| Distance | 19.41 ± 0.02 ly (5.952 ± 0.005 pc) |
| 36 Oph B | |
| Radial velocity (Rv) | 0.0 km/s |
| Proper motion (μ) | RA: −465.861 mas/yr Dec.: −1,141.168 mas/yr |
| Parallax (π) | 168.1303 ± 0.1081 mas |
| Distance | 19.40 ± 0.01 ly (5.948 ± 0.004 pc) |
| 36 Oph C | |
| Radial velocity (Rv) | −0.04±0.22 km/s |
| Proper motion (μ) | RA: −479.573 mas/yr Dec.: −1,124.332 mas/yr |
| Parallax (π) | 167.9617±0.0311 mas |
| Distance | 19.418 ± 0.004 ly (5.954 ± 0.001 pc) |
| Orbit | |
| Primary | 36 Oph A |
| Companion | 36 Oph B |
| Period (P) | 470.9 yr |
| Semi-major axis (a) | 13″ |
| Eccentricity (e) | 0.916 |
| Inclination (i) | 99.8° |
| Details | |
| 36 Oph A | |
| Mass | 0.75+0.02 −0.04 M☉ |
| Radius | 0.817±0.016 R☉ |
| Luminosity | 0.326±0.084 L☉ |
| Temperature | 5,103±29 K |
| Metallicity [Fe/H] | −0.23 dex |
| Rotation | 20.69±0.40 days |
| Age | 1.43 Gyr |
| 36 Oph B | |
| Mass | 0.76+0.03 −0.06 M☉ |
| Radius | 0.721±0.044 R☉ |
| Luminosity | 0.32 L☉ |
| Surface gravity (log g) | 4.61 cgs |
| Temperature | 5,171±71 K |
| Metallicity [Fe/H] | −0.22 dex |
| Rotation | 21.11±0.40 days |
| Age | 1.43 Gyr |
| 36 Oph C | |
| Mass | 0.72±0.01 M☉ |
| Radius | 0.688±0.064 R☉ |
| Luminosity | 0.14 L☉ |
| Surface gravity (log g) | 4.70 cgs |
| Temperature | 4,474±22 K |
| Metallicity [Fe/H] | −0.22 dex |
| Rotation | 18.0±0.4 days |
| Age | 590±70 Myr |
| Other designations | |
| 36 Oph, WDS J17153-2636 | |
| AB: GJ 663, CD−26°12026, GCTP 3908.00, HIP 84405 | |
| A: Guniibuu, HR 6402, HD 155886, LHS 437, SAO 185198 | |
| B: HR 6401, HD 155885, LHS 438, SAO 185199 | |
| C: V2215 Ophiuchi, GJ 664, CD−26°12036, HD 156026, GCTP 3913.00, LHS 439, SAO 185213, HIP 84478 | |
| Database references | |
| SIMBAD | AB |
| A | |
| B | |
| C | |
| Exoplanet Archive | B |
| C | |
| ARICNS | A |
| B | |
| C | |
36 Ophiuchi (or Guniibuu for component A) is a triple star system 19.5 light-years from Earth in the constellation Ophiuchus.