Astronomy:Xi2 Ceti
| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| Constellation | Cetus |
| Right ascension | 02h 28m 09.55706s[1] |
| Declination | +08° 27′ 36.2168″[1] |
| Apparent magnitude (V) | +4.279[2] |
| Characteristics | |
| Spectral type | B9.5III[3] or A0III-[4] |
| U−B color index | −0.137[5] |
| B−V color index | −0.053±0.003[5] |
| Astrometry | |
| Radial velocity (Rv) | 11.90±1.3[6] km/s |
| Proper motion (μ) | RA: 23.707±0.844[1] mas/yr Dec.: −4.787±0.778[1] mas/yr |
| Parallax (π) | 16.5681 ± 0.4608[1] mas |
| Distance | 197 ± 5 ly (60 ± 2 pc) |
| Absolute magnitude (MV) | +0.45[5] |
| Details | |
| Mass | 2.45[7] M☉ |
| Radius | 2.60±0.17[8] R☉ |
| Luminosity | 80.13[5] L☉ |
| Surface gravity (log g) | 4.00±0.25[8] cgs |
| Temperature | 10,630±400[9] K |
| Metallicity [Fe/H] | −0.43±0.04[5] dex |
| Rotational velocity (v sin i) | 55[7] km/s |
| Age | 127[7] Myr |
| Other designations | |
| Database references | |
| SIMBAD | data |
| Exoplanet Archive | data |
Xi2 Ceti, Latinized from ξ2 Ceti, is a star located in the equatorial constellation of Cetus. It is visible to the naked eye with an apparent visual magnitude of +4.3.[2] This star is located at a distance of approximately 197 light years from the Sun based on parallax, and is drifting further away with a radial velocity of 12 km/s.[6] It made its closest approach some 2.7 million years ago at a distance of around 128 light-years.[5]
Xi2 Ceti is a spectrophotometric standard star.[2] It displays a stellar classification of B9.5III,[3] which suggests it has exhausted its core hydrogen, evolved away from the main sequence, and expanded to become a giant star, although still only 127 million years old.[7] It has 2.45[7] times the mass and 2.6[8] times the radius of the Sun.
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 Xi2 Ceti itself is "the Sixth Star of Circular Celestial Granary", Tiān Qūn Liù.[10]
References
- ↑ 1.0 1.1 1.2 1.3 1.4 Brown, A. G. A. (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics 616: A1. doi:10.1051/0004-6361/201833051. Bibcode: 2018A&A...616A...1G. Gaia DR2 record for this source at VizieR.
- ↑ 2.0 2.1 2.2 Bessell, Michael S. (1999). "Spectrophotometry: Revised Standards and Techniques". Publications of the Astronomical Society of the Pacific 111 (765): 1426–1433. doi:10.1086/316454. Bibcode: 1999PASP..111.1426B.
- ↑ 3.0 3.1 Cowley, A. et al. (April 1969). "A study of the bright A stars. I. A catalogue of spectral classifications". Astronomical Journal 74: 375–406. doi:10.1086/110819. Bibcode: 1969AJ.....74..375C.
- ↑ Gray, R. O.; Garrison, R. F. (1987). "The Early A-Type Stars: Refined MK Classification, Confrontation with Stroemgren Photometry, and the Effects of Rotation". The Astrophysical Journal Supplement Series 65: 581. doi:10.1086/191237. Bibcode: 1987ApJS...65..581G.
- ↑ 5.0 5.1 5.2 5.3 5.4 5.5 Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters 38 (5): 331. doi:10.1134/S1063773712050015. Bibcode: 2012AstL...38..331A.
- ↑ 6.0 6.1 Gontcharov, G. A. (November 2006). "Pulkovo Compilation of Radial Velocities for 35495 Hipparcos stars in a common system". Astronomy Letters 32 (11): 759–771. doi:10.1134/S1063773706110065. Bibcode: 2006AstL...32..759G.
- ↑ 7.0 7.1 7.2 7.3 7.4 David, Trevor J.; Hillenbrand, Lynne A. (2015). "The Ages of Early-type Stars: Strömgren Photometric Methods Calibrated, Validated, Tested, and Applied to Hosts and Prospective Hosts of Directly Imaged Exoplanets". The Astrophysical Journal 804 (2): 146. doi:10.1088/0004-637X/804/2/146. Bibcode: 2015ApJ...804..146D.
- ↑ 8.0 8.1 8.2 Gordon, Kathryn D. et al. (2019). "Angular Sizes, Radii, and Effective Temperatures of B-type Stars from Optical Interferometry with the CHARA Array". The Astrophysical Journal 873 (1): 91. doi:10.3847/1538-4357/ab04b2. Bibcode: 2019ApJ...873...91G.
- ↑ Zorec, J. et al. (2009). "Fundamental parameters of B supergiants from the BCD system. I. Calibration of the (λ_1, D) parameters into Teff". Astronomy and Astrophysics 501 (1): 297–320. doi:10.1051/0004-6361/200811147. Bibcode: 2009A&A...501..297Z. http://www.aanda.org/articles/aa/full_html/2009/25/aa11147-08/aa11147-08.html.
- ↑ (in Chinese) AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 7 月 11 日
External links
- Kaler, James B. (Dec 17, 2007). "Xi-2 Ceti". STARS. http://stars.astro.illinois.edu/sow/xi2cet.html.
- http://server3.wikisky.org/starview?object_type=1&object_id=889
- http://www.alcyone.de/cgi-bin/search.pl?object=HR0718
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