Omicron Ophiuchi

Double star in the constellation Ophiuchus

Omicron Ophiuchi
Observation data Epoch J2000 Equinox J2000
Constellation	Ophiuchus
A
Right ascension	17^h 18^m 00.68112^s^[1]
Declination	−24° 17′ 12.8535″^[1]
Apparent magnitude (V)	5.14^[2]
B
Right ascension	17^h 18^m 00.60620^s^[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 (R_v)	−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 (M_V)	0.38^[2]
B
Radial velocity (R_v)	−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 (M_V)	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
ο Oph, 39 Ophiuchi, CD−24°13255, CCDM J17180-2417, WDS J17180-2417
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

^ ^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.

Constellation of Ophiuchus

Stars

Bayer	α (Rasalhague) β (Cebalrai) γ (Muliphen) δ (Yed Prior) ε (Yed Posterior) ζ (Han) η (Sabik) θ ι κ λ (Marfik) μ ν ξ ο ρ σ τ υ φ χ ψ ω
Flamsteed	12 14 15 16 18 19 20 21 23 24 26 28 29 30 31 36 (A, Guniibuu) 37 38 41 43 44 (b) 45 (d, θ Tel) 50 51 (c) 52 53 (f) 54 58 61 66 67 68 70 (p) 71 72 73 74 24 Sco
Variable	U V X Y RS RV RZ ST SW TT TW UU WZ XX BF IX KK V380 V426 V438 V442 V445 V451 V453 V502 V508 V566 V567 V716 V839 V841 V849 V986 V1010 V1054 V2051 V2052 V2076 V2105 V2112 V2113 V2114 V2118 V2126 V2129 V2213 V2214 V2247 V2291 V2292 V2293 V2295 V2301 V2306 V2307 V2324 V2368 V2388 V2393 V2400 V2487 V2500 (Barnard's Star) V2502 V2540 V2542
HR	5989 5990 6041 6067 6096 6124 6136 6137 6140 6144 6179 6189 6190 6193 6201 6202 6235 6248 6269 6284 6294 6296 6302 6308 6329 6340 6350 6353 6354 6358 6359 6361 6365 6367 6372 6375 6387 6390 6404 6413 6428 6433 6435 6439 6441 6465 6472 6473 6474 6476 6489 6490 6494 6497 6504 6507 6512 6516 6520 6521 6524 6532 6534 6575 6577 6578 6590 6593 6601 6633 6639 6650 6659 6667 6670 6686 6689 6690 6696 6706 6719 6784 6797 6800 6851 6857 6883 6902 6925 6976 6985 6987 7010
HD	148390 148427 (Timir) 148531 149143 (Rosalíadecastro) 149382 150052 150381 150433 150493 152581 (Mahsati) 154088 156992 157172 160042 160346 164509 167162 170469 171028
Other	AS 239 BD-9 4395 CFHTWIR-Oph 98 CoRoT-6 CoRoT-25 CoRoT-26 DoAr 21 Elias 2-27 Gaia BH1 Gliese 673 GJ 1207 GJ 1214 GRS 1739-278 GX 1+4 GX 9+9 H 1705-250 Hen 3-1341 Great Annihilator IRAS 16293−2422 K2-32 LS IV-1 2 2MASS J16452211-1319516 MXB 1659-29 Oph-IRS 48 PG 1627-017 PSR B1929+10 TOI-677 Van Biesbroeck 8 VVV BD001 WISE 1800+0134 WISEP J180026.60+013453.1 Wolf 635 XTE J1739-285

Exoplanets	CFHTWIR-Oph 98 b CoRoT-6b 25b 26b GJ 1214 b (Enaiposha) ν Ophiuchi b c

Star
clusters

NGC	6284 6287 6293 6304 6316 6325 6342 6355 6356 6366 6401 6426 6633
Other	IC 4665 Melotte 186 Messier 9 Messier 10 Messier 12 Messier 14 Messier 19 Messier 62 Messier 107 Palomar 6

Nebulae

NGC	6309 6572
Other	Dark Horse Double Helix Nebula Ophiuchus Superbubble Pipe Nebula Rho Ophiuchi cloud complex Serpens–Aquila Rift Snake Nebula