Sigma Cassiopeiae
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Cassiopeia |
| Right ascension | 23h 59m 00.538s[1] |
| Declination | +55° 45′ 17.74″[1] |
| Apparent magnitude (V) | +4.88 |
| Characteristics | |
| Spectral type | B1V |
| U−B color index | −0.82 |
| B−V color index | −0.07 |
| Variable type | none |
| Astrometry | |
| Radial velocity (Rv) | −13 km/s |
| Proper motion (μ) | RA: 8.14 ± 0.34[1] mas/yr Dec.: −5.01 ± 0.32[1] mas/yr |
| Parallax (π) | 0.72 ± 0.43[1] mas |
| Distance | approx. 5,000 ly (approx. 1,400 pc) |
| Absolute magnitude (MV) | −3.46 |
| Other designations | |
Sigma Cassiopeiae (σ Cas, σ Cassiopeiae) is a binary star in the constellation Cassiopeia. It is approximately 5000 light years from Earth[1] and has a combined apparent magnitude of +4.88.
The primary component, σ Cassiopeiae A, is a blue-white B-type giant with an apparent magnitude of +5.0. Its companion, σ Cassiopeiae B, is a blue-white B-type main sequence dwarf, with an apparent magnitude of +7.1. The two stars are 3.1 arcseconds apart.
Naming
In Chinese, 螣蛇 (Téng Shé), meaning Flying Serpent, refers to an asterism consisting of σ Cassiopeiae, α Lacertae, 4 Lacertae, π2 Cygni, π1 Cygni, HD 206267, ε Cephei, β Lacertae, ρ Cassiopeiae, τ Cassiopeiae, AR Cassiopeiae, 9 Lacertae, 3 Andromedae, 7 Andromedae, 8 Andromedae, λ Andromedae, κ Andromedae, ι Andromedae, and ψ Andromedae. Consequently, σ Cassiopeiae itself is known as 螣蛇十一 (Téng Shé shíyī, English: the Eleventh Star of Flying Serpent)[2]
References
- 1 2 3 4 5 6 van Leeuwen, F. (2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics 474 (2): 653–664. arXiv:0708.1752. Bibcode:2007A&A...474..653V. doi:10.1051/0004-6361:20078357.Vizier catalog entry
- ↑ (Chinese) AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 7 月 7 日
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