Sigma Aquarii
 Location of σ Aquarii (circled) |
|
| Observation data Epoch J2000 Equinox J2000 |
|
|---|---|
| Constellation | Aquarius |
| Right ascension | 22h 30m 38.81546s[1] |
| Declination | –10° 40′ 40.6238″[1] |
| Apparent magnitude (V) | 4.81[2] |
| Characteristics | |
| Spectral type | A0 IVs[3] |
| U−B color index | –0.14[2] |
| B−V color index | –0.08[2] |
| Astrometry | |
| Radial velocity (Rv) | +11[4] km/s |
| Proper motion (μ) | RA: +0.30[1] mas/yr Dec.: –26.87[1] mas/yr |
| Parallax (π) | 11.26 ± 1.26[1] mas |
| Distance | approx. 290 ly (approx. 89 pc) |
| Details | |
| Surface gravity (log g) | 3.75[5] cgs |
| Temperature | 10,125[5] K |
| Rotational velocity (v sin i) | 22[5] km/s |
| Other designations | |
| Data sources: | |
| Hipparcos Catalogue, CCDM (2002), Bright Star Catalogue (5th rev. ed.) |
|
Sigma Aquarii (σ Aqr, σ Aquarii) is the Bayer designation for a double star in the equatorial constellation of Aquarius. It is visible to the naked eye with an apparent visual magnitude of 4.81.[2] Based upon parallax measurements, the distance to this star is roughly 290 light-years (89 parsecs).[1]
Sigma Aquarii is an astrometric binary with an orbital period of 654 days.[citation needed] The primary component has a stellar classification of A0 IVs,[3] indicating that it is a subgiant star. This is categorized as an Am star, meaning that it is a chemically peculiar. The spectrum displays at least double the normal abundances of elements like magnesium, aluminum and silicon, while helium and scandium are under-abundant.
In Japanese, 貴子星 (Takako-boshi), meaning "Precious Girl Star," refers to the Japanese description of σ Aquarii.
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.
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