20 Ceti

20 Ceti

Observation data Epoch J2000      Equinox J2000
Constellation	Cetus
Right ascension	00^h 53^m 00.49452^s[1]
Declination	−01° 08′ 39.3317″[1]
Apparent magnitude (V)	4.76[2]
Characteristics
Spectral type	K5 III[3]
U−B color index	+1.91[4]
B−V color index	+1.56[4]
Astrometry
Radial velocity (Rv)	+16.22±0.28[5] km/s
Proper motion (μ)	RA: +6.99[1] mas/yr Dec.: −15.66[1] mas/yr
Parallax (π)	5.56 ± 0.22 mas[1]
Distance	590 ± 20 ly (180 ± 7 pc)
Absolute magnitude (MV)	−1.58[6]
Details[7]
Radius	65.93+2.13 −2.25 R☉
Luminosity	754.8±52.6 L☉
Surface gravity (log g)	1.63 cgs
Temperature	3,724±35 K
Other designations
BD−01° 114, FK5 1022, HD 5112, HIP 4147, HR 248, SAO 129009[8]
Database references
SIMBAD	data

20 Ceti is a single^[9] star located around 590^[1] light years away in the equatorial constellation of Cetus. It is faintly visible to the naked eye with apparent magnitude is 4.76.^[2] The Bright Star Catalogue has this star classified as M0III,^[10] matching an aging red giant star that has consumed the hydrogen at its core and expanded. Houk and Swift (1999) listed an earlier class of K5 III.^[3] It has around 60 times the Sun's radius and is radiating about 800 times the Sun's luminosity from its enlarged photosphere at an effective temperature of 3,700 K.^[7]

References

1. 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, S2CID 18759600.
2. Ducati, J. R. (2002), "VizieR Online Data Catalog: Catalogue of Stellar Photometry in Johnson's 11-color system", CDS/ADC Collection of Electronic Catalogues, 2237, Bibcode:2002yCat.2237....0D.
3. Houk, N.; Swift, C. (1999), "Michigan catalogue of two-dimensional spectral types for the HD Stars", Michigan Spectral Survey, 5, Ann Arbor, Michigan: Department of Astronomy, University of Michigan, Bibcode:1999MSS...C05....0H.
4. Mermilliod, J.-C. (1986), "Compilation of Eggen's UBV data, transformed to UBV (unpublished)", Catalogue of Eggen's UBV Data, Bibcode:1986EgUBV........0M.
5. Famaey, B.; Pourbaix, D.; Frankowski, A.; Van Eck, S.; Mayor, M.; Udry, S.; Jorissen, A. (2009), "Spectroscopic binaries among Hipparcos M giants", Astronomy and Astrophysics, 498 (2): 627, arXiv:0901.0934, Bibcode:2009A&A...498..627F, doi:10.1051/0004-6361/200810698, S2CID 18739721.
6. Groenewegen, M. A. T. (April 2012), "Infrared excess around nearby red giant branch stars and Reimers law", Astronomy & Astrophysics, 540: 21, Bibcode:2012A&A...540A..32G, doi:10.1051/0004-6361/201118287, A32.
7. Baines, Ellyn K.; Thomas Armstrong, J.; Clark, James H.; Gorney, Jim; Hutter, Donald J.; Jorgensen, Anders M.; Kyte, Casey; Mozurkewich, David; Nisley, Ishara; Sanborn, Jason; Schmitt, Henrique R.; Van Belle, Gerard T. (2021). "Angular Diameters and Fundamental Parameters of Forty-four Stars from the Navy Precision Optical Interferometer". The Astronomical Journal. 162 (5): 198. arXiv:2211.09030. Bibcode:2021AJ....162..198B. doi:10.3847/1538-3881/ac2431. S2CID 238998021.
8. "20 Cet". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved December 26, 2018.
9. Eggleton, P. P.; Tokovinin, A. A. (September 2008), "A catalogue of multiplicity among bright stellar systems", Monthly Notices of the Royal Astronomical Society, 389 (2): 869–879, arXiv:0806.2878, Bibcode:2008MNRAS.389..869E, doi:10.1111/j.1365-2966.2008.13596.x, S2CID 14878976.
10. Hoffleit, D.; Warren, Jr., W. H. (1991), The Bright Star Catalogue (5th Revised ed.), New Haven: Yale University Observatory, Bibcode:1991bsc..book.....H.