| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Ophiuchus |
| Right ascension | 17h34m 36.69409s[1] |
| Declination | +09° 35′ 12.1005″[1] |
| Apparent magnitude (V) | 5.80[2] (5.82 + 7.8)[3] |
| Characteristics | |
| Spectral type | A2 V + A8 IV[4] |
| Astrometry | |
| 53 Oph A | |
| Radial velocity (Rv) | −13.9±2.9[5] km/s |
| Proper motion (μ) | RA: +2.126[1] mas/yr Dec.: −8.530[1] mas/yr |
| Parallax (π) | 8.8060 ± 0.0978 mas[1] |
| Distance | 370 ± 4 ly (114 ± 1 pc) |
| 53 Oph B | |
| Proper motion (μ) | RA: +1.794[6] mas/yr Dec.: −8.148[6] mas/yr |
| Parallax (π) | 8.8979 ± 0.0413 mas[6] |
| Distance | 367 ± 2 ly (112.4 ± 0.5 pc) |
| Details | |
| 53 Oph Aa | |
| Mass | 2.50±0.05[7] M☉ |
| Radius | 1.7[8] R☉ |
| Luminosity | 56.4+5.3 −4.9[7] L☉ |
| Surface gravity (log g) | 3.90[9] cgs |
| Temperature | 9,311+173 −170[7] K |
| Metallicity [Fe/H] | 0.21[9] dex |
| Rotational velocity (v sin i) | 29[7] km/s |
| 53 Oph B | |
| Radius | 1.72+0.06 −0.03[6] R☉ |
| Luminosity | 7.74±0.05[6] L☉ |
| Temperature | 7,344+124 −152[6] K |
| Rotational velocity (v sin i) | 140[4] km/s |
| Other designations | |
f Oph, 53 Oph, HD 159480, HIP 85998, HR 6548, WDS J17346+0935[10] | |
| 53 Oph A: BD+09°3424, GC 23824, SAO 122526[10] | |
| 53 Oph B: BD+09°3423, GC 23823, SAO 122525[11] | |
| Database references | |
| SIMBAD | data |
53 Ophiuchi is a multiple star system in the equatorial constellationofOphiuchus. It is visible to the naked eye as a faint star with a combined apparent visual magnitude of 5.80.[3] Located around 370 light years distant from the Sun based on parallax,[1] it is moving closer to the Earth with a heliocentric radial velocity of −14 km/s.[5] As of 2011, the visible components had an angular separationof41.28″ along a position angle of 190°.[12] The primary may itself be a close binary system with a separation of 0.3692″ and a magnitude difference of 3.97 at an infrared wavelength of 562 nm.[13]
The magnitude 5.82[3] primary, designated component Aa, is an A-type main-sequence star with a stellar classification of A2 V.[4] It has 2.5[7] times the mass of the Sun and about 1.7[8] times the Sun's radius. The star is radiating 56 times the Sun's luminosity from its photosphere at an effective temperature of 9,311 K.[7] The widely spaced secondary, designated component B, is a magnitude 7.8[3] A-type subgiant star with a class of A8 IV.[4]
