Astronomy:Sigma Cassiopeiae
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| Observation data {{#ifeq:J2000.0|J2000.0 (ICRS)|Epoch J2000.0 Equinox J2000.0 (ICRS)| Epoch J2000.0 [[Astronomy:Equinox (celestial coordinates)|Equinox J2000.0}} | |
|---|---|
| Constellation | Cassiopeia |
| σ Cas A | |
| Right ascension | 23h 59m 00.538s[1] |
| Declination | +55° 45′ 17.75″[1] |
| Apparent magnitude (V) | 5.01[2] |
| σ Cas B | |
| Right ascension | 23h 59m 00.331s[3] |
| Declination | +55° 45′ 20.37″[3] |
| Apparent magnitude (V) | 7.24[2] |
| Characteristics | |
| σ Cas A | |
| Spectral type | B2 IV[4] |
| U−B color index | −0.82 |
| B−V color index | −0.07 |
| Variable type | β Cep?[5] |
| σ Cas B | |
| Spectral type | B3 V[4] |
| Astrometry | |
| σ Cas A | |
| Radial velocity (Rv) | −12.6[6] km/s |
| Proper motion (μ) | RA: +9.956[1] mas/yr Dec.: −4.492[1] mas/yr |
| Parallax (π) | 2.7419 ± 0.1491[1] mas |
| Distance | 1,190 ± 60 ly (360 ± 20 pc) |
| Absolute magnitude (MV) | −3.90[5] |
| Radial velocity (Rv) | −5.0[6] km/s |
| Proper motion (μ) | RA: +8.651[3] mas/yr Dec.: −3.739[3] mas/yr |
| Parallax (π) | 2.2572 ± 0.0558[3] mas |
| Distance | 1,440 ± 40 ly (440 ± 10 pc) |
| Absolute magnitude (MV) | −1.7[4] |
| Details[5] | |
| A | |
| Mass | 12 M☉ |
| Radius | 11.3 R☉ |
| Luminosity | 25,000 L☉ |
| Surface gravity (log g) | 3.6 cgs |
| Temperature | 21,000 K |
| Rotational velocity (v sin i) | 170 km/s |
| Age | 15.8 Myr |
| Other designations | |
| Database references | |
| SIMBAD | data |
Sigma Cassiopeiae (σ Cas, σ Cassiopeiae) is a binary star in the constellation Cassiopeia. It is 1,200 to 1,400 light years from Earth and has a combined apparent magnitude of +4.88.[7]
The primary component, σ Cassiopeiae A, is a B2 subgiant with an apparent magnitude of +5.0. Its companion, σ Cassiopeiae B, is a B5 main sequence dwarf with an apparent magnitude of +7.1. The two stars are three arcseconds apart.[8]
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, the Chinese name for σ Cassiopeiae itself is 螣蛇十一 (Téng Shé shíyī, English: the Eleventh Star of Flying Serpent).[9]
References
- ↑ 1.0 1.1 1.2 1.3 1.4 Vallenari, A. et al. (2022). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy & Astrophysics. doi:10.1051/0004-6361/202243940 Gaia DR3 record for this source at VizieR.
- ↑ 2.0 2.1 Høg, E.; Fabricius, C.; Makarov, V. V.; Urban, S.; Corbin, T.; Wycoff, G.; Bastian, U.; Schwekendiek, P. et al. (2000). "The Tycho-2 catalogue of the 2.5 million brightest stars". Astronomy and Astrophysics 355: L27. Bibcode: 2000A&A...355L..27H.
- ↑ 3.0 3.1 3.2 3.3 3.4 Vallenari, A. et al. (2022). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy & Astrophysics. doi:10.1051/0004-6361/202243940 Gaia DR3 record for this source at VizieR.
- ↑ 4.0 4.1 4.2 Abt, H. A.; Cardona, O. (1983). "Confirmation among visual multiples of an increase of AP stars with age". Astrophysical Journal 272: 182. doi:10.1086/161276. Bibcode: 1983ApJ...272..182A.
- ↑ 5.0 5.1 5.2 Catanzaro, G.; Ventura, R.; Ferrara, F.; Paternò, L. (2010). "Spectroscopic analysis of the candidate β Cephei star σ Cas: Atmospheric characterization and line-profile variability". New Astronomy 15 (1): 39. doi:10.1016/j.newast.2009.05.001. Bibcode: 2010NewA...15...39C.
- ↑ 6.0 6.1 Kharchenko, N.V.; Scholz, R.-D.; Piskunov, A.E.; Röser, S.; Schilbach, E. (November 2007). "Astrophysical supplements to the ASCC-2.5: Ia. Radial velocities of ~55000 stars and mean radial velocities of 516 Galactic open clusters and associations". Astronomische Nachrichten 328 (9): 889–896. doi:10.1002/asna.200710776. ISSN 0004-6337. Bibcode: 2007AN....328..889K.
- ↑ Nicolet, B. (1978). "Catalogue of homogeneous data in the UBV photoelectric photometric system". Astronomy and Astrophysics 34: 1. Bibcode: 1978A&AS...34....1N.
- ↑ Mason, Brian D.; Wycoff, Gary L.; Hartkopf, William I.; Douglass, Geoffrey G.; Worley, Charles E. (2001). "The 2001 US Naval Observatory Double Star CD-ROM. I. The Washington Double Star Catalog". The Astronomical Journal 122 (6): 3466. doi:10.1086/323920. Bibcode: 2001AJ....122.3466M.
- ↑ (in 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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