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