Rho Ceti

Rho Ceti , Latinized from ρ Ceti, is the Bayer designation for a star in the equatorial constellation of Cetus. It is faintly visible to the naked eye with an apparent visual magnitude of 4.885.^[2] The distance to this star, based upon an annual parallax shift of 7.15 mas,^[1] is around 460 light years.

Rho Ceti

Observation data Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation	Cetus
Right ascension	02h 25m 57.00560s[1]
Declination	−12° 17′ 25.7104″[1]
Apparent magnitude (V)	4.885[2]
Characteristics
Spectral type	A0 V[3]
U−B color index	+0.001[2]
B−V color index	−0.037[2]
Astrometry
Radial velocity (Rv)	+18.9±2.0[4] km/s
Proper motion (μ)	RA: −11.28[1] mas/yr Dec.: −9.48[1] mas/yr
Parallax (π)	7.15±0.26 mas[1]
Distance	460 ± 20 ly (140 ± 5 pc)
Absolute magnitude (MV)	−0.85[5]
Details
Radius	3.1[6] R☉
Luminosity	178[7] L☉
Temperature	8,905[7] K
Rotational velocity (v sin i)	219[8] km/s
Other designations
ρ Cet, 72 Cet, BD−12°451, FK5 1066, HD 15130, HIP 11345, HR 708, SAO 148385.[9]
Database references
SIMBAD	data

This is an A-type main sequence star with a stellar classification of A0 V.^[3] It is spinning rapidly with a projected rotational velocity of 219^[8] km/s, giving the star an oblate shape with an equatorial bulge that is 10% larger than the polar radius.^[10] The star has an estimated size 3.1^[6] times the radius of the Sun and is radiating 178 times the solar luminosity from its outer atmosphere at an effective temperature of 8,905 K.^[7]

Name

This star, along with π Cet, ε Cet and σ Cet, was Al Sufi's Al Sadr al Ḳaiṭos, the Whale's Breast ^[11]

According to the catalogue of stars in the Technical Memorandum 33-507 - A Reduced Star Catalog Containing 537 Named Stars, Al Sadr al Ḳaiṭos were the title for four stars :this star (ρ Cet) as Al Sadr al Ḳaiṭos I, σ Cet as Al Sadr al Ḳaiṭos II, ε Cet as Al Sadr al Ḳaiṭos III and π Cet as Al Sadr al Ḳaiṭos IV^[12]

In Chinese, 芻蒿 (Chú Hāo), meaning Hay, refers to an asterism consisting of ρ Ceti, 77 Ceti, 67 Ceti, 71 Ceti, HD 14691^[13] and ε Cet. Consequently, the Chinese name for ρ Ceti itself is 芻蒿一 (Chú Hāo yī, English: the First Star of Celestial Meadows.^[14]