Global InformationRho2 Eridani information
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Eridanus |
| Right ascension | 03h 02m 42.28856s[1] |
| Declination | −07° 41′ 07.7165″[1] |
| Apparent magnitude (V) | 5.32[2] |
| Characteristics | |
| Spectral type | K0 III[3] |
| U−B color index | +0.73[2] |
| B−V color index | +0.94[2] |
| Astrometry | |
| Radial velocity (Rv) | 26.38±0.23[4] km/s |
| Proper motion (μ) | RA: +49.30[1] mas/yr Dec.: −5.42[1] mas/yr |
| Parallax (π) | 12.32 ± 1.23 mas[1] |
| Distance | 260 ± 30 ly (81 ± 8 pc) |
| Absolute magnitude (MV) | 0.830[5] |
| Details | |
| Mass | 2.53[5] M☉ |
| Radius | 9[4] R☉ |
| Luminosity | 45.7[4] L☉ |
| Surface gravity (log g) | 2.6[4] cgs |
| Temperature | 4,864[4] K |
| Metallicity [Fe/H] | 0.19[5] dex |
| Rotational velocity (v sin i) | 0.0[4] km/s |
| Other designations | |
ρ2 Eridani, ρ2 Eri, 9 Eridani, BD−08°568, HD 18953, HIP 14168, HR 917, SAO 130254.[6] | |
| Database references | |
| SIMBAD | data |
Rho2 Eridani is a star located in the constellation Eridanus. It forms an asterism with Rho1 and Rho3 Eridani, south of Cetus, in the upper north east portion of Eridanus. The star has an apparent visual magnitude of 5.32,[2] which indicates it is visible to the naked eye on a clear, dark night. Based upon parallax measurements made with the Hipparcos satellite, this star is roughly 260 light years away from the Sun.
This is an evolved K-type giant star with a stellar classification of K0 III.[3] It is a red clump giant on the horizontal branch of the Hertzsprung–Russell diagram, indicating that is it now generating energy through the thermonuclear fusion of helium at its core.[5] The star has 2.5 times the mass of the Sun and has expanded to 9 times the Sun's radius. As such, it is radiating nearly 46 times the solar luminosity from its outer atmosphere at an effective temperature of 4,864 K.[4]
There is a magnitude 9.7 companion star at an angular separation of 1.8″. Most likely the pair form a binary star system.[7] At least one of the stars appears to be a source of X-ray emission.[8] The X-ray band flux is 3.65×10−15 W·m−2.[9]
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