Xi1 Ceti
Xi1 Ceti (ξ1 Ceti), is a binary system located in the constellation Cetus, suspected as a ternary.
Observation data Epoch J2000.0 Equinox J2000.0 | |
---|---|
Constellation | Cetus |
Right ascension | 02h 12m 59.995s[1] |
Declination | +08° 50′ 48.16″[1] |
Apparent magnitude (V) | +4.37 [combined] |
Characteristics | |
Spectral type | G6/8 III[2] |
Astrometry | |
Proper motion (μ) | RA: –26.87 ± 0.48[1] mas/yr Dec.: –17.23 ± 0.36[1] mas/yr |
Parallax (π) | 8.51 ± 0.51[1] mas |
Distance | 380 ± 20 ly (118 ± 7 pc) |
Absolute magnitude (MV) | –0.866[2] |
Details | |
Mass | 4[2] M☉ |
Luminosity | 190[2] L☉ |
Temperature | 4200[2] K |
Age | 300[2] Myr |
Other designations | |
Database references | |
SIMBAD | data |
Exoplanet Archive | data |
In Chinese, 天囷 (Tiān Qūn), meaning Circular Celestial Granary, refers to an asterism consisting of α Ceti, κ1 Ceti, λ Ceti, μ Ceti, ξ1 Ceti, ξ2 Ceti, ν Ceti, γ Ceti, δ Ceti, 75 Ceti, 70 Ceti, 63 Ceti and 66 Ceti. Consequently, the Chinese name for Xi1 Ceti itself is "the Fifth Star of Circular Celestial Granary", Tiān Qūn Wu.[3]
The spectroscopic binary nature of Xi1 Ceti was discovered in 1901 by William Wallace Campbell using the Mills spectrograph at the Lick Observatory.[4][5] The primary Ceti A is a G6III or G8III clump-giant star. The spectroscopic binary companion star is an A2V dwarf of about 2 solar masses and 30 luminosity. It is separated at 0.012 arcsec so in an orbit of 4.2 AU, smaller than the distance between Jupiter and the Sun.
Xi1 Ceti A exhibits characteristics similar to an eclipsing binary, with a small white dwarf companion. Occultations with the moon have not yet confirmed the existence of the second suspected companion. However, component A is a barium star which would tend to confirm this unseen component.[6]
References
- 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
- Jim Kaler (Dec 21, 2007). "Xi-1 Ceti".
- (in Chinese) AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 7 月 11 日
- Campbell, William Wallace (1901). "Some recent results secured with the Mills spectrograph". Lick Observatory Bulletin. 1 (4): 22–25. Bibcode:1901LicOB...1...22C. doi:10.5479/ADS/bib/1901LicOB.1.22C.
- Griffin, R. F.; Herbig, G. H. (1981). "Spectroscopic Orbits of Xi Piscium 60 Andromedae and ξ1 Ceti". Monthly Notices of the Royal Astronomical Society. 196: 33–43. Bibcode:1981MNRAS.196...33G. doi:10.1093/mnras/196.1.33.
- Pinsonneault, M. H.; et al. (March 1984), "Lithium in the barium stars", Publications of the Astronomical Society of the Pacific, 96: 239–246, Bibcode:1984PASP...96..239P, doi:10.1086/131327.