Phi2 Ceti

For other stars with this Bayer designation, see φ Ceti.

φ^2 Ceti

Observation data Epoch J2000      Equinox J2000
Constellation	Cetus
Right ascension	00^h 50^m 07.58859^s[1]
Declination	−10° 38′ 39.5848″[1]
Apparent magnitude (V)	5.172[2]
Characteristics
Spectral type	F7V[3]
U−B color index	+0.009[2]
B−V color index	+0.518[2]
Astrometry
Radial velocity (Rv)	+8.23±0.17[1] km/s
Proper motion (μ)	RA: –226.91[4] mas/yr Dec.: –229.75[4] mas/yr
Parallax (π)	62.9723 ± 0.1614 mas[1]
Distance	51.8 ± 0.1 ly (15.88 ± 0.04 pc)
Absolute magnitude (MV)	4.23[5]
Details
Mass	1.19[6] M☉
Radius	1.17+0.03 −0.01[1] R☉
Luminosity	1.852+0.006 −0.007[1] L☉
Surface gravity (log g)	4.45[6] cgs
Temperature	6,352[6] K
Metallicity [Fe/H]	−0.03[6] dex
Rotational velocity (v sin i)	4.3[7] km/s
Age	1.9[6] Gyr
Other designations
φ^2 Cet, 19 Cet, NSV 316, BD−11° 153, GJ 37, HD 4813, HIP 3909, HR 235, SAO 147470
Database references
SIMBAD	data

Phi² Ceti, Latinized from φ² Ceti), is a star located in the equatorial constellation of Cetus. φ² Ceti is also known as 19 Cet, and HD 4813. Based upon parallax measurements, it is located about 51 light years away. It has an apparent visual magnitude of +5.19, making it bright enough to be seen with the naked eye. The star is drifting further away with a radial velocity of +8 km/s.^[1]

This is an ordinary F-type main sequence star with a stellar classification of F7V. The star is estimated to be 1.9^[6] billion years old and is spinning with a projected rotational velocity of 4.3 km/s.^[7] It has 1.2^[6] times the mass and 1.17^[1] times the radius of the Sun. The star is radiating 1.85^[1] times the luminosity of the Sun from its photosphere at an effective temperature of 6,352 K.^[6] It is a suspected variable star of unknown type, with a brightness that has been measured ranging from magnitude 5.15 down to 5.24.^[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. Gaia DR2 record for this source at VizieR.
2. Gutierrez-Moreno, Adelina; et al. (1966), "A System of photometric standards", Publications of the Department of Astronomy University of Chile, 1, Publicaciones Universidad de Chile, Department de Astronomy: 1–17, Bibcode:1966PDAUC...1....1G.
3. Gray, R. O.; et al. (2006), "Contributions to the Nearby Stars (NStars) Project: spectroscopy of stars earlier than M0 within 40 pc-The Southern Sample", The Astronomical Journal, 132 (1): 161–70, arXiv:astro-ph/0603770, Bibcode:2006AJ....132..161G, doi:10.1086/504637, S2CID 119476992.
4. van Leeuwen, F. (November 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.
5. Paunzen, E.; et al. (July 2014), "Investigating the possible connection between λ Bootis stars and intermediate Population II type stars", Astronomy & Astrophysics, 567: 8, arXiv:1406.3936, Bibcode:2014A&A...567A..67P, doi:10.1051/0004-6361/201423817, S2CID 56332289, A67.
6. Bensby, T.; et al. (2014), "Exploring the Milky Way stellar disk. A detailed elemental abundance study of 714 F and G dwarf stars in the solar neighbourhood", Astronomy & Astrophysics, 562 (A71): 28, arXiv:1309.2631, Bibcode:2014A&A...562A..71B, doi:10.1051/0004-6361/201322631, S2CID 118786105.
7. Schröder, C.; Reiners, Ansgar; Schmitt, Jürgen H. M. M. (January 2009), "Ca II HK emission in rapidly rotating stars. Evidence for an onset of the solar-type dynamo" (PDF), Astronomy and Astrophysics, 493 (3): 1099–1107, Bibcode:2009A&A...493.1099S, doi:10.1051/0004-6361:200810377^{[permanent dead link‍]}
8. Samus, N. N.; et al. (2017), "General Catalogue of Variable Stars", Astronomy Reports, 5.1, 61 (1): 80–88, Bibcode:2017ARep...61...80S, doi:10.1134/S1063772917010085, S2CID 125853869.