Omicron Ophiuchi
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Ophiuchus |
| A | |
| Right ascension | 17h 18m 00.68112s[1] |
| Declination | −24° 17′ 12.8535″[1] |
| Apparent magnitude (V) | 5.14[2] |
| B | |
| Right ascension | 17h 18m 00.60620s[3] |
| Declination | −24° 17′ 02.8150″[3] |
| Apparent magnitude (V) | 6.59[2] |
| Characteristics | |
| A | |
| Spectral type | G8III[2] |
| U−B color index | 0.98[4] |
| B−V color index | 1.046±0.005[2] |
| B | |
| Spectral type | F6IV-V[2] |
| U−B color index | 0.05[4] |
| B−V color index | 0.510±0.015[2] |
| Astrometry | |
| A | |
| Radial velocity (Rv) | −28.97±0.13[1] km/s |
| Proper motion (μ) | RA: −57.544[1] mas/yr Dec.: −7.725[1] mas/yr |
| Parallax (π) | 11.5763 ± 0.1756 mas[1] |
| Distance | 282 ± 4 ly (86 ± 1 pc) |
| Absolute magnitude (MV) | 0.38[2] |
| B | |
| Radial velocity (Rv) | −29.70[5] km/s |
| Proper motion (μ) | RA: −56.561[3] mas/yr Dec.: −12.457[3] mas/yr |
| Parallax (π) | 11.6213 ± 0.0603 mas[3] |
| Distance | 281 ± 1 ly (86.0 ± 0.4 pc) |
| Absolute magnitude (MV) | 1.66[2] |
| Details | |
| A | |
| Radius | 12.30+0.20 −0.32[1] R☉ |
| Luminosity | 75.3±1.3[1] L☉ |
| Surface gravity (log g) | 2.69[6] cgs |
| Temperature | 4,849+63 −40[1] K |
| Metallicity [Fe/H] | 0.33[6] dex |
| B | |
| Radius | 2.99+0.10 −0.12[3] R☉ |
| Luminosity | 12.629±0.086[3] L☉ |
| Temperature | 6,296+130 −105[3] K |
| Metallicity [Fe/H] | 0.23±0.08[2] dex |
| Other designations | |
| A: GC 23344, HD 156349, HIP 84626, HR 6424, SAO 185238[7] | |
| B: GC 23343, HD 156350, HIP 84625, HR 6425, SAO 185237[8] | |
| Database references | |
| SIMBAD | AB |
| A | |
| B | |
ο Ophiuchi, Latinized as Omicron Ophiuchi, is a wide double star in the equatorial constellation of Ophiuchus. The co-moving pair are visible to the naked eye as a dim point of light, with the two components having apparent visual magnitudes of 5.14 and 6.59.[2] As of 2015, they had an angular separation of 10.0″ along a position angle of 354°.[9] The distance to both stars is approximately 281 light years based on parallax, and they are drifting closer to the Sun with a radial velocity of around −29 km/s.[5]
The brighter member of the pair, designated component A, is an aging giant star with a stellar classification of G8III.[2] With the supply of hydrogen at its core exhausted, it has expanded to 12[1] times the radius of the Sun. The star is radiating 75[1] times the Sun's luminosity from its enlarged photosphere at an effective temperature of 4,849 K.[1] The secondary star, component B, has a class of F6IV-V,[2] matching an F-type star with a luminosity class that is a blend of traits from a main sequence and a subgiant star. It has three[3] times the Sun's radius and is radiating 12.6 times the Sun's luminosity at 6,296 K.[3]
References[edit]
- ^ a b c d e f g h i j k l Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR.
- ^ a b c d e f g h i j k l Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters. 38 (5): 331. arXiv:1108.4971. Bibcode:2012AstL...38..331A. doi:10.1134/S1063773712050015. S2CID 119257644.
- ^ a b c d e f g h i j Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR.
- ^ a b Mermilliod, J.-C. (1986). "Compilation of Eggen's UBV data, transformed to UBV (unpublished)". Catalogue of Eggen's UBV Data. Bibcode:1986EgUBV........0M.
- ^ a b Gontcharov, G. A. (2006). "Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system". Astronomy Letters. 32 (11): 759–771. arXiv:1606.08053. Bibcode:2006AstL...32..759G. doi:10.1134/S1063773706110065. S2CID 119231169.
- ^ a b Luck, R. Earle (2014). "Parameters and Abundances in Luminous Stars". The Astronomical Journal. 147 (6): 137. Bibcode:2014AJ....147..137L. doi:10.1088/0004-6256/147/6/137.
- ^ "omi Oph A". SIMBAD. Centre de données astronomiques de Strasbourg.
- ^ "omi Oph B". SIMBAD. Centre de données astronomiques de Strasbourg.
- ^ Mason, Brian D.; et al. (2001). "The 2001 US Naval Observatory Double Star CD-ROM. I. The Washington Double Star Catalog". The Astronomical Journal. 122 (6): 3466. Bibcode:2001AJ....122.3466M. doi:10.1086/323920.
