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30 Ophiuchi
Location of 30 Ophiuchi (circled)
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]
Distance350 ± 6  ly
(107 ± 2  pc)
Absolute magnitude (MV)−0.65 [2]
Details
Radius35.89+0.54
−2.12
[1]  R
Luminosity299.8±6.2 [1]  L
Surface gravity (log g)1.73 [7]  cgs
Temperature4,009.00+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
30 Oph, NSV 8111, BD−04°4215, FK5 1445, GC 22937, HD 153687, HIP 83262, HR 6318, SAO 141483, CCDM J17011-0413A, WDS J17011-0413A [9]
Database references
SIMBAD data

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]

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

  1. ^ 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.
  2. ^ 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
  3. ^ 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.
  4. ^ 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
  5. ^ 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.
  6. ^ 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
  7. ^ 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.
  8. ^ 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
  9. ^ "30 Oph". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2019-06-19.
  10. ^ 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.
  11. ^ O'Meara, Stephen James (1998). Deep-Sky Companions: The Messier Objects. Cambridge University Press. p. 63. ISBN  9780521553322.
  12. ^ 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.
  13. ^ 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.
  14. ^ 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.
  15. ^ 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