Astronomy:63 Ophiuchi

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Short description: Star in the constellation Sagittarius
63 Ophiuchi
Observation data
Epoch J2000.0   Equinox (celestial coordinates)
Constellation Sagittarius
Right ascension  17h 54m 54.04315s[1]
Declination −24° 53′ 13.5444″[1]
Apparent magnitude (V) 6.20[2]
Characteristics
U−B color index –0.89[3]
B−V color index +0.04[3]
Astrometry
Radial velocity (Rv)–11[4] km/s
Proper motion (μ) RA: +0.704[1] mas/yr
Dec.: –2.194[1] mas/yr
Parallax (π)0.9071 ± 0.0882[1] mas
Distance3,600 ± 300 ly
(1,100 ± 100 pc)
Absolute magnitude (MV)−6.0[5]
Details
Surface gravity (log g)3.5[6] cgs
Temperature34,000[6] K
Rotational velocity (v sin i)35[6]-86[7] km/s
Other designations
Database references
SIMBADdata

63 Ophiuchi is an O-type giant star in the constellation Sagittarius, despite its name. During a 2009 survey for companions of massive stars, it was observed using speckle interferometry but no companion was found.[8] The small parallax measurement of 0.91±0.09 mas suggest that this extremely luminous star may be located about 3,600 light-years away. An estimate of the distance based on the strength of the Ca II line yields a more modest value of 2,605 ly (799 pc).[9] The star lies only 0.3° north of the galactic plane.

In 1983, astronomers from the Sternberg Astronomical Institute in Moscow, Russia identified a faint, shell-shaped nebula surrounding the star that was being excited by the star's energy. Named Sharpless 22, this ring-shaped nebula has a double-shell structure with an inner envelope spanning 45–50 (9–18 pc), surrounded by a diffuse envelope some 65–80′ (14–29 pc) across. At an estimated mass loss rate of (6–8) × 10−6 M/yr, it would take the star about (1–5) × 105 years to produce such a nebula from the outflow of its stellar wind.[10]

References

  1. 1.0 1.1 1.2 1.3 1.4 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. Ducati, J. R. (2002). "VizieR Online Data Catalog: Catalogue of Stellar Photometry in Johnson's 11-color system". CDS/ADC Collection of Electronic Catalogues 2237. Bibcode2002yCat.2237....0D. 
  3. 3.0 3.1 Schild, R. E. et al. (April 1983), "UBV photometry for southern OB stars", Astrophysical Journal Supplement Series 51: 321–336, doi:10.1086/190852, Bibcode1983ApJS...51..321S 
  4. Wilson, Ralph Elmer (1953), "General catalogue of stellar radial velocities", Washington (Carnegie Institution of Washington), Bibcode1953GCRV..C......0W 
  5. Schröder, S. E.; Kaper, L.; Lamers, H. J. G. L. M.; Brown, A. G. A. (2004). "On the Hipparcos parallaxes of O stars". Astronomy and Astrophysics 428: 149–157. doi:10.1051/0004-6361:20047185. Bibcode2004A&A...428..149S. 
  6. 6.0 6.1 6.2 Martins, F.; Hervé, A.; Bouret, J.-C.; Marcolino, W.; Wade, G. A.; Neiner, C.; Alecian, E.; Grunhut, J. et al. (2015). "The MiMeS survey of magnetism in massive stars: CNO surface abundances of Galactic O stars". Astronomy & Astrophysics 575: A34. doi:10.1051/0004-6361/201425173. Bibcode2015A&A...575A..34M. 
  7. Hubrig, S. et al. (November 2008), "Magnetic field measurements of O stars with FORS 1 at the VLT", Astronomy and Astrophysics 490 (2): 793–800, doi:10.1051/0004-6361:200810171, Bibcode2008A&A...490..793H 
  8. Mason, Brian D. et al. (February 2009), "The High Angular Resolution Multiplicity of Massive Stars", The Astronomical Journal 137 (2): 3358–3377, doi:10.1088/0004-6256/137/2/3358, Bibcode2009AJ....137.3358M 
  9. Megier, A. et al. (November 2009), "The interstellar Ca II distance scale", Astronomy and Astrophysics 507 (2): 833–840, doi:10.1051/0004-6361/20079144, Bibcode2009A&A...507..833M 
  10. Lozinskaya, T. A. et al. (June 1983), "A New Search for Ring Nebulae around Of-Stars - SHARPLESS22", Soviet Astronomy Letters 9 (6): 344–345, Bibcode1983SvAL....9..344L