| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Hydra |
| Right ascension | 09h 54m 12.32596s[1] |
| Declination | −25° 55′ 56.3631″[1] |
| Apparent magnitude (V) | 4.88[2] |
| Characteristics | |
| Spectral type | K2+ III CN0.5[3] |
| B−V color index | 1.23[2] |
| Astrometry | |
| Radial velocity (Rv) | 50.5[2] km/s |
| Proper motion (μ) | RA: −187.764[1] mas/yr Dec.: +52.746[1] mas/yr |
| Parallax (π) | 12.5809 ± 0.2161 mas[1] |
| Distance | 259 ± 4 ly (79 ± 1 pc) |
| Absolute magnitude (MV) | −0.23[4] |
| Details | |
| Mass | 1.55[2] M☉ |
| Luminosity | 178[2] L☉ |
| Surface gravity (log g) | 2.35[5] cgs |
| Temperature | 4,415±25[2] K |
| Metallicity [Fe/H] | −0.03[5] dex |
| Age | 4.34[2] Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
HD 85859 is a single[7] star in the equatorial constellation of Hydra. It has an apparent visual magnitude of 4.88,[2] which is bright enough to be visible to the naked eye. The distance to this star, as estimated from its annual parallax shift of 12.6 mas,[1] is 259 light years. It is moving away from the Earth with a heliocentric radial velocity of 50.5 km/s.[2]
The stellar classification of the visible component is K2+ III CN0.5,[3] which matches an evolved K-type giant star with a mild overabundance of CN in the atmosphere. At the age of 4.34[2] billion years, it is a red clump star, which indicates it is on the horizontal branch and is generating energy through helium fusion at its core.[8] The star has 1.55[2] times the mass of the Sun and is radiating 178[2] times the Sun's luminosity from its enlarged photosphere at an effective temperature of 4,415 K.[2]
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