| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Cetus |
| Right ascension | 00h03m 44.38784s[1] |
| Declination | −17° 20′ 09.5719″[1] |
| Apparent magnitude (V) | 4.483[2] |
| Characteristics | |
| Spectral type | B9 IVn[3] |
| U−B color index | −0.12[4] |
| B−V color index | −0.047±0.003[5] |
| Astrometry | |
| Radial velocity (Rv) | +8.0±4.6[6] km/s |
| Proper motion (μ) | RA: +25.17[1] mas/yr Dec.: −9.16[1] mas/yr |
| Parallax (π) | 11.98 ± 0.26 mas[1] |
| Distance | 272 ± 6 ly (83 ± 2 pc) |
| Absolute magnitude (MV) | −0.06[5] |
| Details | |
| Mass | 2.68±0.11[7] M☉ |
| Radius | 2.75[7] R☉ |
| Luminosity | 119+6 −5[8] L☉ |
| Surface gravity (log g) | 3.99±0.09[7] cgs |
| Temperature | 11,419±388[9] K |
| Metallicity [Fe/H] | +0.00±0.24[3] dex |
| Rotational velocity (v sin i) | 116[8] or 237[10] km/s |
| Age | 217[9] Myr |
| Other designations | |
2 Cet, BD−18° 6417, FK5 905, HD 225132, HIP 301, HR 9098, SAO 147059[11] | |
| Database references | |
| SIMBAD | data |
2 Ceti is a single[12] star in the equatorial constellationofCetus, near the border with Aquarius. It is visible to the naked eye with an apparent visual magnitude of 4.483.[2] The distance to 2 Ceti can be estimated from its annual parallax shiftof12.0 mas,[1] which yields a value of around 272 light years. It appears to be moving further from the Earth with a heliocentric radial velocity of about +8 km/s.[6]
The stellar classification for this star is B9 IVn,[3] matching a B-type subgiant star with "nebulous" absorption lines due to rapid rotation.[13] Estimates of the rotation rate range from 116[8] to 237[10] km/s, and this high rate of spin is giving the star an equatorial bulge that is 12% larger than the polar radius.[13] 2 Ceti is about 217[9] million years old with 2.7[7] times the mass of the Sun and 2.75[7] times the Sun's radius. It is radiating 119[8] times the Sun's luminosity from its photosphere at an effective temperature of 11,419 K.[9]Aninfrared excess has been detected around this star by the Akari satellite at a wavelength of 18μm, suggesting there is an orbiting debris disk.[14]
