Rho Ceti
A-type main sequence star in the constellation Cetus
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Rho Ceti is a star in the equatorial constellation of Cetus. Its name is a Bayer designation that is Latinized from ρ Ceti, and abbreviated Rho Cet or ρ Cet. This star is faintly visible to the naked eye with an apparent visual magnitude of 4.885.[3] The distance to this star, based upon an annual parallax shift of 5.81 mas,[2] is around 560 light years. It is drifting further away with a line of sight velocity component of +19 km/s.[6]
 | |
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Cetus[1] |
| Right ascension | 02h 25m 57.006s[2] |
| Declination | −12° 17′ 25.708″[2] |
| Apparent magnitude (V) | 4.885[3] |
| Characteristics | |
| Evolutionary stage | subgiant[4] |
| Spectral type | A0 V[5] |
| U−B color index | +0.001[3] |
| B−V color index | −0.037[3] |
| Astrometry | |
| Radial velocity (Rv) | +18.9±2.0[6] km/s |
| Proper motion (μ) | RA: −11.596 mas/yr[2] Dec.: −9.786 mas/yr[2] |
| Parallax (π) | 5.8054±0.1358 mas[2] |
| Distance | 560 ± 10 ly (172 ± 4 pc) |
| Absolute magnitude (MV) | −0.85[1] |
| Details | |
| Mass | 2.3[7] M☉ |
| Radius | 6.3[8] R☉ |
| Luminosity | 328[9] L☉ |
| Surface gravity (log g) | 3.56[10] cgs |
| Temperature | 9,505[10] K |
| Rotational velocity (v sin i) | 219[11] km/s |
| Age | 72[7] Myr |
| Other designations | |
| ρ Cet, 72 Cet, BD−12°451, FK5 1066, HD 15130, HIP 11345, HR 708, SAO 148385[12] | |
| Database references | |
| SIMBAD | data |
This star has a stellar classification of A0 V,[5] which is presenting as an A-type main sequence star. However, it may be in the subgiant stage of its evolution.[4] It is spinning rapidly with a projected rotational velocity of 219[11] km/s, giving the star an oblate shape with an equatorial bulge that is 10% larger than the polar radius.[13] The star has an estimated size 6.3 times the radius of the Sun[8] and is radiating 328 times the solar luminosity[9] from its outer atmosphere at an effective temperature of 9,505 K.[10]
Name
This star, along with π Cet, ε Cet and σ Cet, was Al Sufi's Al Sadr al Ḳaiṭos, the Whale's Breast.[14]
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.[15]
In Chinese, 芻蒿 (Chú Hāo), meaning Hay, refers to an asterism consisting of ρ Ceti, 77 Ceti, 67 Ceti, 71 Ceti, HD 14691[16] 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.[17]