Sigma Arietis
 Location of σ Arietis (circled) |
|
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) |
|
|---|---|
| Constellation | Aries |
| Right ascension | 02h 51m 29.58609s[1] |
| Declination | +15° 04′ 55.4500″[1] |
| Apparent magnitude (V) | +5.52[2] |
| Characteristics | |
| Spectral type | B7 V[3] |
| U−B color index | –0.43[2] |
| B−V color index | –0.09[2] |
| Astrometry | |
| Radial velocity (Rv) | +17.0[4] km/s |
| Proper motion (μ) | RA: +30.13[1] mas/yr Dec.: –23.68[1] mas/yr |
| Parallax (π) | 6.60 ± 0.32[1] mas |
| Distance | 490 ± 20 ly (152 ± 7 pc) |
| Details | |
| Mass | 3.84 ± 0.08[5] M☉ |
| Radius | 3[6] R☉ |
| Luminosity | 301[5] L☉ |
| Temperature | 13,121[5] K |
| Rotational velocity (v sin i) | 165[5] km/s |
| Other designations | |
Sigma Arietis (σ Ari, σ Arietis) is the Bayer designation for a star in the northern constellation of Aries. It has an apparent visual magnitude of +5.52,[2] which is bright enough for the star to be seen with the naked eye from dark suburban skies. Based upon an annual measured parallax shift of 6.60 ± 0.32 mas,[1] it is approximately 494 light-years (151 parsecs) distant from the Earth.
Sigma Arietis is a B-type main sequence star with a stellar classification of B7 V.[3] This is a large star with three[6] times the radius of the Sun and 3.8[5] times the Sun's mass. It shines around 301[5] times as brightly as the Sun, with this energy being radiated into space from its outer atmosphere at a scorching hot effective temperature of 13,121 K.[5] It is this heat that gives the star the blue-white hue of a B-type star. Sigma Arietis is spinning at a rapid clip, with a projected rotational velocity of 165 km/s.[5] It is a probable member of the Cas-Tau OB association of stars that share a common motion through space.[8]
References
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- ↑ 2.0 2.1 2.2 2.3 Lua error in package.lua at line 80: module 'strict' not found.
- ↑ 3.0 3.1 Lua error in package.lua at line 80: module 'strict' not found.
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
- ↑ 5.0 5.1 5.2 5.3 5.4 5.5 5.6 5.7 Lua error in package.lua at line 80: module 'strict' not found.
- ↑ 6.0 6.1 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.
