Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
---|---|
Constellation | Eridanus |
Right ascension | 04h 52m 53.66995s[1] |
Declination | −05° 27′ 09.6972″[1] |
Apparent magnitude (V) | 4.37[2] |
Characteristics | |
Spectral type | A9 IVn[3] |
U−B color index | +0.12[2] |
B−V color index | +0.26[2] |
Astrometry | |
Radial velocity (Rv) | −8.3[4] km/s |
Proper motion (μ) | RA: −17.86[1] mas/yr Dec.: +25.57[1] mas/yr |
Parallax (π) | 13.88 ± 0.24 mas[1] |
Distance | 235 ± 4 ly (72 ± 1 pc) |
Absolute magnitude (MV) | 0.10[5] |
Orbit[6] | |
Period (P) | 3,057 d |
Eccentricity (e) | 0.46 |
Periastron epoch (T) | 2419973.0 JD |
Argument of periastron (ω) (secondary) | 227° |
Semi-amplitude (K1) (primary) | 18.1 km/s |
Details | |
Radius | 6.7[7] R☉ |
Luminosity | 69[8] L☉ |
Surface gravity (log g) | 3.4[5] cgs |
Temperature | 6,878[8] K |
Metallicity [Fe/H] | 0.18[5] dex |
Rotational velocity (v sin i) | 186[9] km/s |
Other designations | |
Database references | |
SIMBAD | data |
Omega Eridani (ω Eri) is a binary star[9] system in the constellation Eridanus. It is visible to the naked eye with an apparent visual magnitude is 4.37.[2] The distance to this star, as determined by the parallax method, is around 235 light years.
This is a single-lined spectroscopic binary[11] system with an orbital period of 3,057 days (8.4 years) and an eccentricity of 0.46. The primary component is an A-type subgiant star with a stellar classification of A9 IVn,[3] where the 'n' suffix indicates a broad ("nebulous") absorption due to rotation. The projected rotational velocity is 186[9] km/s.[9] This is giving the star an oblate shape with an equator that is 13% wider than the polar radius. The angular size of Omega Eridani is 0.87 mas.[12] At an estimated distance of the star, this yields a physical size of around 6.7 times the radius of the Sun.[7]