Categories
Zeta Cephei
Topic: Astronomy
From HandWiki - Reading time: 5 min
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| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| Constellation | Cepheus |
| Right ascension | 22h 10m 51.277s[1] |
| Declination | +58° 12′ 04.54″[1] |
| Apparent magnitude (V) | 3.35[2] |
| Characteristics | |
| Evolutionary stage | Red supergiant |
| Spectral type | K1.5 Ib[3] |
| B−V color index | +1.55[2] |
| Variable type | Eclipsing binary?[4] |
| Astrometry | |
| Proper motion (μ) | RA: 13.359±0.148[1] mas/yr Dec.: 5.275±0.183[1] mas/yr |
| Parallax (π) | 3.2972 ± 0.1456[1] mas |
| Distance | 992.7+51.2 −46 ly (304.5+15.7 −14.1 pc) |
| Absolute magnitude (MV) | −4.7[5] |
| Details | |
| Mass | 10.1±0.1[6] M☉ |
| Radius | 172.7+7.5 −8.3[7] R☉ |
| Luminosity | 10,024±1,052[7] L☉ |
| Surface gravity (log g) | 0.75[8] cgs |
| Temperature | 4,393±58[7] K |
| Metallicity [Fe/H] | +0.04[7] dex |
| Rotational velocity (v sin i) | 10.64[9] km/s |
| Other designations | |
| Database references | |
| SIMBAD | data |
Zeta Cephei (ζ Cep, ζ Cephei) is a red supergiant star, located about 1000 light-years away in the constellation of Cepheus. Zeta Cephei marks the left shoulder of Cepheus, the King of Ethiopia. It is one of the fundamental stars of the MK spectral sequence, defined as type K1.5 Ib.
Characteristics
Zeta Cephei has a spectral classification of K1.5Ib,[3] indicating that it is a lower luminosity red supergiant star. It is about 173 times larger than the Sun and has a surface temperature of 4,393 K.[7] The luminosity of Zeta Cephei is approximately 10,000 times that of the Sun.[7] At a distance of about 840 light-years,[10] Zeta Cephei has an apparent magnitude (m) of 3.4 and an absolute magnitude (M) of -4.7. The star has a metallicity approximately 1.6 times that of the Sun; i.e., it contains 1.6 times as much heavy-element material as the Sun.
At a mass of 10.1 M☉, Zeta Cephei might end its life in a core-collapse supernova, and has been listed as a likely pre-supernova candidate by a 2022 study. It could also provide observable pre-supernova neutrino signals, just hours before the core collapses.[6]
Possible companion star
Hekker et al. (2008) have detected a periodicity of 533 days, hinting at the possible presence of an as yet unseen companion.[11] It is listed as a possible eclipsing binary with a very small amplitude.[4]
References
- ↑ 1.0 1.1 1.2 1.3 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 Ducati, J. R. (2002-01-01). "VizieR Online Data Catalog: Catalogue of Stellar Photometry in Johnson's 11-color system.". VizieR Online Data Catalog 2237. Bibcode: 2002yCat.2237....0D. https://ui.adsabs.harvard.edu/abs/2002yCat.2237....0D. Zeta Cephei's database entry at VizieR.
- ↑ 3.0 3.1 Morgan, W. W.; Keenan, P. C. (1973). "Spectral Classification". Annual Review of Astronomy and Astrophysics 11: 29–50. doi:10.1146/annurev.aa.11.090173.000333. Bibcode: 1973ARA&A..11...29M.
- ↑ 4.0 4.1 Samus, N. N. et al. (2009). "VizieR Online Data Catalog: General Catalogue of Variable Stars (Samus+ 2007–2013)". VizieR On-line Data Catalog: B/GCVS. Originally Published in: 2009yCat....102025S 1: 02025. Bibcode: 2009yCat....102025S.
- ↑ Luck, R. E. (1982). "The chemical composition of late-type supergiants. IV - Homogeneous abundances and galactic metallicity trends". Astrophysical Journal 256: 177. doi:10.1086/159895. Bibcode: 1982ApJ...256..177L.
- ↑ 6.0 6.1 Machado, L. N.; Abe, K.; Hayato, Y.; Hiraide, K.; Ieki, K.; Ikeda, M.; Kameda, J.; Kanemura, Y. et al. (2022-08-12). "Pre-supernova Alert System for Super-Kamiokande" (in en). The Astrophysical Journal 935 (1): 40. doi:10.3847/1538-4357/ac7f9c. ISSN 0004-637X. Bibcode: 2022ApJ...935...40M.
- ↑ 7.0 7.1 7.2 7.3 7.4 7.5 Baines, Ellyn K.; Armstrong, J. Thomas; Clark III, James H.; Gorney, Jim; Hutter, Donald J.; Jorgensen, Anders M.; Kyte, Casey; Mozurkewich, David et al. (2021-11-01). "Angular Diameters and Fundamental Parameters of Forty-Four Stars from the Navy Precision Optical Interferometer". The Astronomical Journal 162 (5): 198. doi:10.3847/1538-3881/ac2431. ISSN 0004-6256. Bibcode: 2021AJ....162..198B.
- ↑ Mallik, Sushma V. (December 1999). "Lithium abundance and mass". Astronomy and Astrophysics 352: 495–507. Bibcode: 1999A&A...352..495M.
- ↑ Hekker, S.; Meléndez, J. (2007). "Precise radial velocities of giant stars. III. Spectroscopic stellar parameters". Astronomy and Astrophysics 475 (3): 1003. doi:10.1051/0004-6361:20078233. Bibcode: 2007A&A...475.1003H.
- ↑ van Leeuwen, F. (2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics 474 (2): 653–664. doi:10.1051/0004-6361:20078357. Bibcode: 2007A&A...474..653V. http://www.aanda.org/articles/aa/full/2007/41/aa8357-07/aa8357-07.html.Vizier catalog entry
- ↑ Hekker (2008). "Precise radial velocities of giant stars. IV. A correlation between surface gravity and radial velocity variation and a statistical investigation of companion properties". Astronomy and Astrophysics 480 (1): 215–222. doi:10.1051/0004-6361:20078321. Bibcode: 2008A&A...480..215H.
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