Astronomy:63 Ophiuchi
| Observation data Epoch J2000.0 Equinox (celestial coordinates) | |
|---|---|
| Constellation | Sagittarius[1] |
| Right ascension | 17h 54m 54.04315s[2] |
| Declination | −24° 53′ 13.5444″[2] |
| Apparent magnitude (V) | 6.20[3] |
| Characteristics | |
| 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[2] mas/yr Dec.: –2.194[2] mas/yr |
| Parallax (π) | 0.9071 ± 0.0882[2] mas |
| Distance | 3,600 ± 300 ly (1,100 ± 100 pc) |
| Absolute magnitude (MV) | −5.14±0.22[6] |
| Details | |
| Mass | 17±4[6] M☉ 29[7] M☉ |
| Radius | 12.0±1.2[6] R☉ |
| Luminosity | 11,500+820 −770[6] L☉ |
| Surface gravity (log g) | 3.51±0.03[6] cgs |
| Temperature | 35,000±300[6] K |
| Rotational velocity (v sin i) | 48±5[6] km/s |
| Age | 3.7[6] Myr |
| Other designations | |
| Database references | |
| SIMBAD | data |
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]
In 2025 the star was found to have a weak magnetic field, which is unusual for giant stars. It is considered an example of an transitional object between main sequence strongly magnetic stars and magnetic supergiants like Alnitak.[6]
References
- ↑ Roman, Nancy G. (1987). "Identification of a constellation from a position". Publications of the Astronomical Society of the Pacific 99 (617): 695. doi:10.1086/132034. Bibcode: 1987PASP...99..695R Constellation record for this object at VizieR.
- ↑ 2.0 2.1 2.2 2.3 2.4 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. Bibcode: 2018A&A...616A...1G. Gaia DR2 record for this source at VizieR.
- ↑ 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.
- ↑ 4.0 4.1 Schild, R. E. et al. (April 1983), "UBV photometry for southern OB stars", Astrophysical Journal Supplement Series 51: 321–336, doi:10.1086/190852, Bibcode: 1983ApJS...51..321S
- ↑ Wilson, Ralph Elmer (1953), "General catalogue of stellar radial velocities", Washington (Carnegie Institution of Washington), Bibcode: 1953GCRV..C......0W
- ↑ 6.0 6.1 6.2 6.3 6.4 6.5 6.6 6.7 6.8 Barron, James A.; Wade, Gregg A.; Holgado, Gonzalo; Simón-Díaz, Sergio (2025-05-16), "A magnetic field detection in the massive O-type bright giant 63 Oph", The Astrophysical Journal 991 (1): 79, doi:10.3847/1538-4357/adf6d9, Bibcode: 2025ApJ...991...79B
- ↑ Blex, Susanne; Haas, Martin; Chini, Rolf (2024). "The rotation rate of single- and double-lined southern O stars: Determining what increases the rotation rate in binaries". Astronomy and Astrophysics 692. doi:10.1051/0004-6361/202450176. Bibcode: 2024A&A...692A.192B.
- ↑ 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, Bibcode: 2009AJ....137.3358M
- ↑ 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, Bibcode: 2009A&A...507..833M
- ↑ Lozinskaya, T. A. et al. (June 1983), "A New Search for Ring Nebulae around Of-Stars - SHARPLESS22", Soviet Astronomy Letters 9 (6): 344–345, Bibcode: 1983SvAL....9..344L
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