Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
---|---|
Constellation | Eridanus |
Right ascension | 04h 33m 30.55236s[1] |
Declination | −29° 45′ 59.3725″[1] |
Apparent magnitude (V) | 4.51[2] |
Characteristics | |
Spectral type | K0 III-IV[3] |
U−B color index | +0.70[2] |
B−V color index | +0.98[2] |
Astrometry | |
Radial velocity (Rv) | +20.89±0.69[4] km/s |
Proper motion (μ) | RA: −114.78[1] mas/yr Dec.: −271.79[1] mas/yr |
Parallax (π) | 25.67 ± 0.24 mas[1] |
Distance | 127 ± 1 ly (39.0 ± 0.4 pc) |
Absolute magnitude (MV) | 1.60[4] |
Details | |
Mass | 1.54[4] M☉ |
Radius | 7.3[5] R☉ |
Luminosity | 24[4] L☉ |
Surface gravity (log g) | 3.09[4] cgs |
Temperature | 4,941[4] K |
Metallicity [Fe/H] | −0.16±0.08[4] dex |
Rotational velocity (v sin i) | 2.15[6] km/s |
Other designations | |
Database references | |
SIMBAD | data |
Upsilon1 Eridani (υ1 Eri) is a single star in the constellation Eridanus. It has an apparent visual magnitude is 4.51,[2] which is bright enough to be faintly visible to the naked eye on a clear, dark night. The distance to this star, as determined using the parallax method,[1] is around 127 light years.
This is an evolved red clump[8] giant star with a stellar classification of K0III-IV.[3] The measured angular diameter, after correction for limb darkening, is 1.74±0.02 mas.[9] At an estimated distance of this star, this yields a physical size of about 7.3 times the radius of the Sun.[5] It has 154%[4] of the Sun's mass and radiates 24 times the solar luminosity from its outer atmosphere at an effective temperature of 4,941 K.[4]