46 Ceti

46 Ceti

Observation data Epoch J2000      Equinox J2000
Constellation	Cetus
Right ascension	01^h 25^m 37.23270^s[1]
Declination	−14° 35′ 55.6414″[1]
Apparent magnitude (V)	4.907[2]
Characteristics
Spectral type	K2+ III–IIIb CN0.5[3]
U−B color index	+1.26[4]
B−V color index	+1.231±0.009[5]
Astrometry
Radial velocity (Rv)	−22.6±0.7[6] km/s
Proper motion (μ)	RA: +44.670[1] mas/yr Dec.: −17.216[1] mas/yr
Parallax (π)	11.9466 ± 0.3140 mas[1]
Distance	273 ± 7 ly (84 ± 2 pc)
Absolute magnitude (MV)	+0.19[5]
Details
Mass	1.38[7] M☉
Radius	19[8] R☉
Luminosity	132[7] L☉
Surface gravity (log g)	2.2[8] cgs
Temperature	4,316±89[7] K
Metallicity [Fe/H]	–0.32[8] dex
Rotational velocity (v sin i)	0.0[8] km/s
Age	4.17[7] Gyr
Other designations
BD−15°266, HD 8705, HIP 6670, HR 412, SAO 147803[9]
Database references
SIMBAD	data

46 Ceti is a single^[10] star in the equatorial constellation of Cetus. It is visible to the naked eye with an apparent visual magnitude of 4.9.^[11] The distance to this star, as determined from an annual parallax shift of 11.9 mas,^[1] is about 273 light years. It is moving closer to the Earth with a heliocentric radial velocity of −23 km/s,^[6] and is expected to come as close as 184 light-years in 2.2 million years.^[5]

At the age of about four billion years,^[7] this is an evolved K-type giant star with a stellar classification of K2+ III–IIIb CN0.5.^[3] The suffix notation CN0.5 indicates a mild overabundance of cyanogen in the stellar atmosphere. It has 1.38^[7] times the mass of the Sun and has expanded to 19^[8] times the Sun's radius. The star is radiating 132^[7] times the Sun's luminosity from its enlarged photosphere at an effective temperature of 4,316 K.^[7] The projected rotational velocity is too small to be measured.^[8]

References

1. Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051.
2. Høg, E.; et al. (2000). "The Tycho-2 catalogue of the 2.5 million brightest stars". Astronomy and Astrophysics. 355: L27. Bibcode:2000A&A...355L..27H. doi:10.1888/0333750888/2862.
3. Keenan, Philip C.; McNeil, Raymond C. (1989). "The Perkins catalog of revised MK types for the cooler stars". Astrophysical Journal Supplement Series. 71: 245. Bibcode:1989ApJS...71..245K. doi:10.1086/191373.
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. Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters. 38 (5): 331. arXiv:1108.4971. Bibcode:2012AstL...38..331A. doi:10.1134/S1063773712050015. S2CID 119257644.
6. Gontcharov, G. A. (2006). "Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system". Astronomy Letters. 32 (11): 759–771. arXiv:1606.08053. Bibcode:2006AstL...32..759G. doi:10.1134/S1063773706110065. S2CID 119231169.
7. Luck, R. Earle (2015). "Abundances in the Local Region. I. G and K Giants". The Astronomical Journal. 150 (3): 88. arXiv:1507.01466. Bibcode:2015AJ....150...88L. doi:10.1088/0004-6256/150/3/88. S2CID 118505114.
8. Massarotti, Alessandro; Latham, David W.; Stefanik, Robert P.; Fogel, Jeffrey (2008). "Rotational and Radial Velocities for a Sample of 761 Hipparcos Giants and the Role of Binarity". The Astronomical Journal. 135 (1): 209–231. Bibcode:2008AJ....135..209M. doi:10.1088/0004-6256/135/1/209.
9. "46 Cet". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved December 27, 2018.
10. 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.
11. Høg, E.; et al. (2000). "The Tycho-2 catalogue of the 2.5 million brightest stars". Astronomy and Astrophysics. 355: L27–L30. Bibcode:2000A&A...355L..27H.