53 Ophiuchi
53 Ophiuchi is a multiple star system in the equatorial constellation of Ophiuchus. It is visible to the naked eye as a faint star with a combined apparent visual magnitude of 5.80. Located around 370 light years distant from the Sun based on parallax, it is moving closer to the Earth with a heliocentric radial velocity of −14 km/s. As of 2011, the visible components had an angular separation of 41.28″ along a position angle of 190°. 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.
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Ophiuchus |
| Right ascension | 17h 34m 36.69409s |
| Declination | +09° 35′ 12.1005″ |
| Apparent magnitude (V) | 5.80 (5.82 + 7.8) |
| Characteristics | |
| Spectral type | A2 V + A8 IV |
| Astrometry | |
| 53 Oph A | |
| Radial velocity (Rv) | −13.9±2.9 km/s |
| Proper motion (μ) | RA: +2.126 mas/yr Dec.: −8.530 mas/yr |
| Parallax (π) | 8.8060 ± 0.0978 mas |
| Distance | 370 ± 4 ly (114 ± 1 pc) |
| 53 Oph B | |
| Proper motion (μ) | RA: +1.794 mas/yr Dec.: −8.148 mas/yr |
| Parallax (π) | 8.8979 ± 0.0413 mas |
| Distance | 367 ± 2 ly (112.4 ± 0.5 pc) |
| Details | |
| 53 Oph Aa | |
| Mass | 2.50±0.05 M☉ |
| Radius | 1.7 R☉ |
| Luminosity | 56.4+5.3 −4.9 L☉ |
| Surface gravity (log g) | 3.90 cgs |
| Temperature | 9,311+173 −170 K |
| Metallicity [Fe/H] | 0.21 dex |
| Rotational velocity (v sin i) | 29 km/s |
| 53 Oph B | |
| Radius | 1.72+0.06 −0.03 R☉ |
| Luminosity | 7.74±0.05 L☉ |
| Temperature | 7,344+124 −152 K |
| Rotational velocity (v sin i) | 140 km/s |
| Other designations | |
| 53 Oph A: BD+09°3424, GC 23824, SAO 122526 | |
| 53 Oph B: BD+09°3423, GC 23823, SAO 122525 | |
| Database references | |
| SIMBAD | data |
The magnitude 5.82 primary, designated component Aa, is an A-type main-sequence star with a stellar classification of A2 V. It has 2.5 times the mass of the Sun and about 1.7 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. The widely spaced secondary, designated component B, is a magnitude 7.8 A-type subgiant star with a class of A8 IV.