Star in the constellation Ophiuchus
30 Ophiuchi Location of 30 Ophiuchi (circled)
Observation dataEpoch J2000 Equinox J2000 Constellation Ophiuchus Right ascension 17h 01m 03.60142s [ 1] Declination −4° 13′ 21.5308″[ 1] Apparent magnitude (V)4.82[ 2] Characteristics Spectral type K4III[ 3] U−Bcolor index +1.80[ 4] B−Vcolor index +1.48[ 4] Astrometry Radial velocity (Rv )−6.70[ 5] km/s Proper motion (μ)RA: −39.13[ 6] mas /yr Dec.: −78.09[ 6] mas /yr Parallax (π)9.3138± 0.1676 mas [ 1] Distance 350 ± 6 ly pc ) Absolute magnitude (MV )−0.65[ 2] Details Radius +0.54 [ 1] R ☉ Luminosity ± 6.2[ 1] L ☉ Surface gravity (log g )1.73[ 7] cgs Temperature +126.67 [ 1] K Metallicity −0.03[ 2] dex Rotational velocity (v sin i )1.4[ 8] Other designations 30 Oph ,NSV 8111BD −04°4215FK5 1445GC 22937HD 153687HIP 83262HR 6318SAO 141483CCDM J17011-0413AWDS J17011-0413A[ 9] Database references SIMBAD data
30 Ophiuchi is a single[ 10] star in theequatorial constellation ofOphiuchus , and figures 0.99° east (specificallyE½S ) of the heart of clusterMessier 10 .[ 11] apparent visual magnitude of 4.82.[ 2] light years based onparallax .[ 6] radial velocity ".[ 5]
This is an aginggiant star with astellar classification of K4III,[ 3] core and expanded to 36[ 1] Sun's radius . It is a suspectedvariable star .[ 12] [ 1] luminosity of the Sun from its swollenphotosphere at aneffective temperature of 4,009 K.[ 1] infrared excess due to circumstellar dust,[ 13] AU × 1025 g[ 14]
The primary presents with twovisual companions : B, at magnitude 9.71 and separation 99.8″, and C, at magnitude 8.75 and separation 220.9″ (3′ 40.9″) .[ 15]
^a b c d e f g h i 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 atVizieR .^a b c d 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 . Vizier catalog entry ^a b Hoffleit, D.; Warren, W. H. (1995). "VizieR Online Data Catalog: Bright Star Catalogue, 5th Revised Ed. (Hoffleit+, 1991)".VizieR On-line Data Catalog: V/50. Originally Published in: 1964BS....C......0H .5050 .Bibcode :1995yCat.5050....0H . ^a b Mallama, A. (2014). "Sloan Magnitudes for the Brightest Stars".The Journal of the American Association of Variable Star Observers .42 (2): 443.Bibcode :2014JAVSO..42..443M . Vizier catalog entry ^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 c Van Leeuwen, F. (2007). "Validation of the new Hipparcos reduction".Astronomy and Astrophysics .474 (2):653– 664.arXiv :0708.1752 Bibcode :2007A&A...474..653V .doi :10.1051/0004-6361:20078357 .S2CID 18759600 . Vizier catalog entry ^ Soubiran, Caroline; Le Campion, Jean-François; Brouillet, Nathalie; Chemin, Laurent (2016). "The PASTEL catalogue: 2016 version".Astronomy & Astrophysics .591 : A118.arXiv :1605.07384 Bibcode :2016A&A...591A.118S .doi :10.1051/0004-6361/201628497 .S2CID 119258214 . ^ De Medeiros, J. R.; Alves, S.; Udry, S.; Andersen, J.; Nordström, B.; Mayor, M. (2014). "A catalog of rotational and radial velocities for evolved stars".Astronomy & Astrophysics .561 : A126.arXiv :1312.3474 Bibcode :2014A&A...561A.126D .doi :10.1051/0004-6361/201220762 .S2CID 54046583 . Vizier catalog entry ^ "30 Oph" .SIMBAD Centre de données astronomiques de Strasbourg . Retrieved2019-06-19 .^ Eggleton, P. P.; Tokovinin, A. A. (September 2008)."A catalogue of multiplicity among bright stellar systems" .Monthly Notices of the Royal Astronomical Society 389 (2):869– 879.arXiv :0806.2878 Bibcode :2008MNRAS.389..869E .doi :10.1111/j.1365-2966.2008.13596.x S2CID 14878976 . ^ O'Meara, Stephen James (1998).Deep-Sky Companions: The Messier Objects ISBN 9780521553322 ^ Samus, N. N.; et al. (2017). "General Catalogue of Variable Stars".Astronomy Reports . 5.1.61 (1):80– 88.Bibcode :2017ARep...61...80S .doi :10.1134/S1063772917010085 .S2CID 125853869 . ^ Zuckerman, B.; et al. (June 1995)."Luminosity Class III Stars with Excess Far-Infrared Emission" .Astrophysical Journal Letters .446 : L79.Bibcode :1995ApJ...446L..79Z .doi :10.1086/187935 ^ Jura, M. (April 1999)."Dust around First-Ascent Red Giants" .The Astrophysical Journal .515 (2):706– 711.Bibcode :1999ApJ...515..706J .doi :10.1086/307064 ^ Mason, Brian D.; Wycoff, Gary L.; Hartkopf, William I.; Douglass, Geoffrey G.; Worley, Charles E. (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 Vizier catalog entry
