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Upsilon2 Eridani
Star in the constellation of Eridanus / From Wikipedia, the free encyclopedia
For other star systems with this Bayer designation, see Upsilon Eridani.
Upsilon2 Eridani (υ² Eridani, abbreviated Upsilon2 Eri, υ2 Eri), officially named Theemin /ˈθiːmən/,[10][11] is a star in the constellation of Eridanus. It is visible to the naked eye with an apparent visual magnitude of 3.8.[2] Based upon parallax measurements obtained during the Hipparcos mission,[1] it is approximately 66 parsecs (214 light-years) from the Sun.
Quick Facts Constellation, Right ascension ...
Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
---|---|
Constellation | Eridanus |
Right ascension | 04h 35m 33.03834s[1] |
Declination | −30° 33′ 44.4297″[1] |
Apparent magnitude (V) | 3.804[2] |
Characteristics | |
Spectral type | G8+ III[3] |
U−B color index | +0.740[2] |
B−V color index | +0.968[2] |
Astrometry | |
Radial velocity (Rv) | −4.0±0.9[4] km/s |
Proper motion (μ) | RA: −49.27[1] mas/yr Dec.: −12.72[1] mas/yr |
Parallax (π) | 15.25 ± 0.19 mas[1] |
Distance | 214 ± 3 ly (65.6 ± 0.8 pc) |
Absolute magnitude (MV) | −0.27[5] |
Details | |
Radius | 16[6] R☉ |
Luminosity | 138[7] L☉ |
Surface gravity (log g) | 2.77±0.07[8] cgs |
Temperature | 5,074±30[8] K |
Metallicity [Fe/H] | 0.04±0.03[8] dex |
Other designations | |
Database references | |
SIMBAD | data |
Close
It is an evolved red clump[12] giant star with a stellar classification of G8+ III.[3] The measured angular diameter is 2.21 mas.[13] At the star's distance, this yields a physical size of around 16 times the radius of the Sun.[6] It radiates 138[7] times the solar luminosity from its outer atmosphere at an effective temperature of 5074 K.[8]