| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Cetus[1] |
| Right ascension | 02h 41m 13.99720s[2] |
| Declination | −00° 41′ 44.3845″[2] |
| Apparent magnitude (V) | 5.709[3] |
| Characteristics | |
| Spectral type | F7V[4] + K2V[5] |
| U−Bcolor index | −0.047[3] |
| B−Vcolor index | +0.522[3] |
| Astrometry | |
| Radial velocity (Rv) | +3.90[6] km/s |
| Proper motion (μ) | RA: +216.51[2]mas/yr Dec.: −129.33[2]mas/yr |
| Parallax (π) | 44.27±0.84 mas[2] |
| Distance | 74 ± 1 ly (22.6 ± 0.4 pc) |
| Absolute magnitude (MV) | +3.95[1] |
| Details | |
| 84 Cet A | |
| Mass | 1.168[4] M☉ |
| Radius | 1.208±0.029[4] R☉ |
| Luminosity | 2.133±0.083[4] L☉ |
| Temperature | 6,356±46[4] K |
| Metallicity[Fe/H] | −0.15[4] dex |
| Rotational velocity (v sin i) | 32.0[7] km/s |
| Age | 2.1[4] Gyr |
| Other designations | |
| 84 Cet,BD−01°377,HD 16765,HIP 12530,HR 790,SAO 130055.[8] | |
| Database references | |
| SIMBAD | data |
84 Ceti is theFlamsteed designation for abinary star system[5] in theequatorialconstellation ofCetus. It has anapparent visual magnitude of 5.7,[3] making itfaintly visible to the naked eye from dark suburban skies.Parallax measurements with theHipparcos spacecraft put this system at a distance of around 74 light years.[2]
The primary, 84 Ceti A, is anF-type main sequence star with astellar classification of F7V. It is slightly larger than the Sun, with 117% of theSun's mass, 121% of theradius, and 213% of theluminosity.[4] The abundance of elements more massive than helium is 71% of the Sun's and it has a relatively highprojected rotational velocity of 32 km/s.[7] This star is estimated to be less than half the age of the Sun, at 2.1 billion years.[4]
The secondary component, 84 Ceti B, has a classification of K2V,[5] making it aK-type main sequence star. It lies at anangular separation of 3.3″ from the primary, which is equivalent to a physical separation of at least 74.5 AU.[5]
Thespace velocity components of this system are: –13(U), –25(V), –2(W) km/s.[9] Based upon the position and motion, it is a candidate member of theTucana-Horologium Association; this is a group of stars that share a similar motion through space and hence may have originated in the samemolecular cloud.[10] 84 Ceti is following an orbit through theMilky Way galaxy that has aneccentricity of 0.03, taking it as close as 22.3 kly (6.83 kpc) and as far as 26.2 kly (8.02 kpc) from theGalactic Center. Theinclination of theorbital plane carries it as far as 260 ly (80 pc) away from thegalactic plane.[9]
