63 Ophiuchi
 The location of 63 Ophiuchi (circled) in the constellation Sagittarius |
|
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) |
|
|---|---|
| Constellation | Sagittarius |
| Right ascension | 17h 54m 54.04380s[1] |
| Declination | −24° 53′ 13.5413″[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: 1.66[1] mas/yr Dec.: –2.63[1] mas/yr |
| Parallax (π) | −0.77 ± 0.40[1] mas |
| Absolute magnitude (MV) | −6.0[6] |
| Details | |
| Surface gravity (log g) | 3.5[7] cgs |
| Temperature | 34,000[7] K |
| Rotational velocity (v sin i) | 35[7]-86[8] km/s |
| 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.[9] Uncertain negative parallax measurements of –0.77 ± 0.40 mas suggest that this extremely luminous star may be located about 4000 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]
References
<templatestyles src="Reflist/styles.css" />
Cite error: Invalid <references> tag; parameter "group" is allowed only.
<references />, or <references group="..." />- ↑ 1.0 1.1 1.2 1.3 1.4 Lua error in package.lua at line 80: module 'strict' not found.
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
- ↑ 4.0 4.1 Lua error in package.lua at line 80: module 'strict' not found.
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
- ↑ 7.0 7.1 7.2 Lua error in package.lua at line 80: module 'strict' not found.
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
