30 Ophiuchi is a single[10] star in the equatorial constellation of Ophiuchus, and figures 0.99° east (specifically E½S) of the heart of cluster Messier 10.[11] It is visible to the naked eye as a faint, orange-hued point of light with an apparent visual magnitude of 4.82.[2] The distance to this star is approximately 350 light years based on parallax.[6] Its present motion is, net, one of approaching rather than parting, at −6.7 km/s, its "radial velocity".[5]
  | |
| Observation data Epoch 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−B color index | +1.80[4] |
| B−V color 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 (107 ± 2 pc) |
| Absolute magnitude (MV) | −0.65[2] |
| Details | |
| Radius | 35.89+0.54 −2.12[1] R☉ |
| Luminosity | 299.8±6.2[1] L☉ |
| Surface gravity (log g) | 1.73[7] cgs |
| Temperature | 4,009.00+126.67 −29.67[1] K |
| Metallicity [Fe/H] | −0.03[2] dex |
| Rotational velocity (v sin i) | 1.4[8] km/s |
| Other designations | |
| Database references | |
| SIMBAD | data |
This is an aging giant star with a stellar classification of K4III,[3] having exhausted the supply of hydrogen at its core and expanded to 36[1] times the Sun's radius. It is a suspected variable star.[12] The star is radiating 300[1] times the luminosity of the Sun from its swollen photosphere at an effective temperature of 4,009 K.[1] It is emitting a far infrared excess due to circumstellar dust,[13] which extends out to a diameter of 240 AU and has a mass of 62×1025 g.[14]
The primary presents with two visual companions: B, at magnitude 9.71 and separation 99.8″, and C, at magnitude 8.75 and separation 220.9″ (3′ 40.9″).[15]
References edit
- ^ 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 at VizieR.
- ^ 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. Retrieved 2019-06-19.
- ^ 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. Cambridge University Press. p. 63. 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