Astronomy:30 Ophiuchi

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Short description: Star in the constellation Ophiuchus
30 Ophiuchi
Ophiuchus constellation map.svg
Red circle.svg
Location of 30 Ophiuchi (circled)
Observation data
Equinox J2000.0]] (ICRS)
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[1] mas
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
SIMBADdata

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 astronomical unit|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. 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 Brown, A. G. A. (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics 616: A1. doi:10.1051/0004-6361/201833051. Bibcode2018A&A...616A...1G.  Gaia DR2 record for this source at VizieR.
  2. 2.0 2.1 2.2 2.3 Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters 38 (5): 331. doi:10.1134/S1063773712050015. Bibcode2012AstL...38..331A.  Vizier catalog entry
  3. 3.0 3.1 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. Bibcode1995yCat.5050....0H. 
  4. 4.0 4.1 Mallama, A. (2014). "Sloan Magnitudes for the Brightest Stars". The Journal of the American Association of Variable Star Observers 42 (2): 443. Bibcode2014JAVSO..42..443M. Vizier catalog entry
  5. 5.0 5.1 Gontcharov, G. A. (2006). "Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system". Astronomy Letters 32 (11): 759–771. doi:10.1134/S1063773706110065. Bibcode2006AstL...32..759G. 
  6. 6.0 6.1 6.2 Van Leeuwen, F. (2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics 474 (2): 653–664. doi:10.1051/0004-6361:20078357. Bibcode2007A&A...474..653V.  Vizier catalog entry
  7. Soubiran, Caroline; Le Campion, Jean-François; Brouillet, Nathalie; Chemin, Laurent (2016). "The PASTEL catalogue: 2016 version". Astronomy & Astrophysics 591: A118. doi:10.1051/0004-6361/201628497. Bibcode2016A&A...591A.118S. 
  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. doi:10.1051/0004-6361/201220762. Bibcode2014A&A...561A.126D.  Vizier catalog entry
  9. "30 Oph". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=30+Oph. 
  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. doi:10.1111/j.1365-2966.2008.13596.x. Bibcode2008MNRAS.389..869E. 
  11. O'Meara, Stephen James (1998). Deep-Sky Companions: The Messier Objects. Cambridge University Press. p. 63. ISBN 9780521553322. https://books.google.com/books?id=jis4evHuuzUC&pg=PA63. 
  12. Samus, N. N. et al. (2017). "General Catalogue of Variable Stars". Astronomy Reports. 5.1 61 (1): 80–88. doi:10.1134/S1063772917010085. Bibcode2017ARep...61...80S. 
  13. Zuckerman, B. et al. (June 1995). "Luminosity Class III Stars with Excess Far-Infrared Emission". Astrophysical Journal Letters 446: L79. doi:10.1086/187935. Bibcode1995ApJ...446L..79Z. 
  14. Jura, M. (April 1999). "Dust around First-Ascent Red Giants". The Astrophysical Journal 515 (2): 706–711. doi:10.1086/307064. Bibcode1999ApJ...515..706J. 
  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. doi:10.1086/323920. Bibcode2001AJ....122.3466M.  Vizier catalog entry