Phi4 Ceti

Phi⁴ Ceti is a solitary,^[7] orange-hued star in the equatorial constellation Cetus. It is faintly visible to the naked eye with an apparent visual magnitude of 5.61.^[2] Based upon an annual parallax shift of 9.76 mas as seen from Earth, it is located approximately 334 light years from the Sun. At that distance, the visual magnitude of the star is diminished by an extinction factor of 0.10 due to interstellar dust,^[4] giving it an absolute magnitude of 0.70.^[5] It is drifting closer with a radial velocity of −19 km/s.^[4]

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

Phi⁴ Ceti

Observation data Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation	Cetus
Right ascension	00h 58m 43.86832s[1]
Declination	−11° 22′ 47.9147″[1]
Apparent magnitude (V)	5.61[2]
Characteristics
Evolutionary stage	Horizontal branch
Spectral type	G8 III[3]
B−V color index	+0.94[2]
Astrometry
Radial velocity (Rv)	−19.24±0.07[4] km/s
Proper motion (μ)	RA: −33.159[1] mas/yr Dec.: −14.202[1] mas/yr
Parallax (π)	9.7623 ± 0.1120 mas[1]
Distance	334 ± 4 ly (102 ± 1 pc)
Absolute magnitude (MV)	0.696[5]
Details[4]
Mass	1.76±0.18 M☉
Radius	11.08+0.35 −0.26[1] R☉
Luminosity	64.9±0.9[1] L☉
Surface gravity (log g)	2.60±0.06 cgs
Temperature	4,903±28 K
Metallicity [Fe/H]	−0.17±0.03 dex
Rotational velocity (v sin i)	0.83±0.48 km/s
Age	1.52 Gyr
Other designations
φ4 Cet, 23 Cet, BD−12°173, HD 5722, HIP 4587, HR 279, SAO 147546[6]
Database references
SIMBAD	data

This is an evolved G-type giant star with a stellar classification of G8 III.^[3] At the estimated age of 1.5 billion years,^[4] is a red clump giant on the horizontal branch, which indicates it is generating energy through helium fusion at its core.^[5] The star has about 1.76^[4] times the mass of the Sun and has expanded to 11 times the Sun's radius.^[1] It is radiating 60 times the solar luminosity from its photosphere at an effective temperature of 4,903 K.^[4]

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. Corben, P. M.; Stoy, R. H. (1968), "Photoelectric Magnitudes and Colours for Bright Southern Stars", Monthly Notes of the Astronomical Society of Southern Africa, 27: 11, Bibcode:1968MNSSA..27...11C.
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. Jofré, E.; et al. (2015), "Stellar parameters and chemical abundances of 223 evolved stars with and without planets", Astronomy & Astrophysics, 574: A50, arXiv:1410.6422, Bibcode:2015A&A...574A..50J, doi:10.1051/0004-6361/201424474, S2CID 53666931, A50.
5. Liu, Y. J.; et al. (2007), "The abundances of nearby red clump giants", Monthly Notices of the Royal Astronomical Society, 382 (2): 553–66, Bibcode:2007MNRAS.382..553L, doi:10.1111/j.1365-2966.2007.11852.x.
6. "phi04 Cet". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2017-04-22.
7. 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.