63 Ophiuchi

63 Ophiuchi
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Sagittarius
Right ascension 17h 54m 54.04315s[1]
Declination −24° 53′ 13.5444″[1]
Apparent magnitude (V) 6.20[2]
Characteristics
Spectral type O8II((f))[3]
U−B color index –0.89[4]
B−V color index +0.04[4]
Astrometry
Radial velocity (Rv)–11[5] km/s
Proper motion (μ) RA: +0.704[1] mas/yr
Dec.: –2.194[1] mas/yr
Parallax (π)0.9071 ± 0.0882 mas[1]
Distance3,600 ± 300 ly
(1,100 ± 100 pc)
Absolute magnitude (MV)−6.0[6]
Details
Surface gravity (log g)3.5[7] cgs
Temperature34,000[7] K
Rotational velocity (v sin i)35[7]-86[8] km/s
Other designations
63 Oph, CD−24° 13615, HD 162978, HIP 87706, HR 6672, SAO 185928
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.[9] 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).[10] 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.[11]

  1. ^ a b c d e 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. ^ 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. Bibcode:2002yCat.2237....0D.
  3. ^ Sota, A.; Maíz Apellániz, J.; Morrell, N. I.; Barbá, R. H.; Walborn, N. R.; Gamen, R. C.; Arias, J. I.; Alfaro, E. J. (2014). "The Galactic O-Star Spectroscopic Survey (GOSSS). II. Bright Southern Stars". The Astrophysical Journal Supplement. 211 (1): 10. arXiv:1312.6222. Bibcode:2014ApJS..211...10S. doi:10.1088/0067-0049/211/1/10. S2CID 118847528.
  4. ^ a b Cite error: The named reference apjss51_321 was invoked but never defined (see the help page).
  5. ^ Cite error: The named reference gcsrv was invoked but never defined (see the help page).
  6. ^ 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. arXiv:astro-ph/0408370. Bibcode:2004A&A...428..149S. doi:10.1051/0004-6361:20047185. S2CID 55115943.
  7. ^ a b c Martins, F.; Hervé, A.; Bouret, J.-C.; Marcolino, W.; Wade, G. A.; Neiner, C.; Alecian, E.; Grunhut, J.; Petit, V. (2015). "The MiMeS survey of magnetism in massive stars: CNO surface abundances of Galactic O stars". Astronomy & Astrophysics. 575: A34. arXiv:1411.4420. Bibcode:2015A&A...575A..34M. doi:10.1051/0004-6361/201425173. S2CID 119258285.
  8. ^ Cite error: The named reference aaa490_2_793 was invoked but never defined (see the help page).
  9. ^ Cite error: The named reference aj137_2_3358 was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference aaa507_2_833 was invoked but never defined (see the help page).
  11. ^ Cite error: The named reference nal9_6_344 was invoked but never defined (see the help page).