6 Hydrae
6 Hydrae is a single star in the equatorial constellation of Hydra, located 373 light-years away from the Sun. It has the Bayer designation a Hydrae; 6 Hydrae is the Flamsteed designation. This object is visible to the naked eye as a faint, orange-hued star with an apparent visual magnitude of 4.98. It is moving closer to the Earth with a heliocentric radial velocity of −8 km/s. Eggen (1995) listed it as a proper motion candidate for membership in the IC 2391 supercluster.
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Hydra |
| Right ascension | 08h 40m 01.47182s |
| Declination | −12° 28′ 31.3433″ |
| Apparent magnitude (V) | 4.98 |
| Characteristics | |
| Evolutionary stage | giant |
| Spectral type | K3 III |
| B−V color index | 1.415±0.001 |
| Astrometry | |
| Radial velocity (Rv) | −7.8±0.6 km/s |
| Proper motion (μ) | RA: −81.619 mas/yr Dec.: −1.646 mas/yr |
| Parallax (π) | 8.7394 ± 0.1769 mas |
| Distance | 373 ± 8 ly (114 ± 2 pc) |
| Absolute magnitude (MV) | −0.40 |
| Details | |
| Radius | 32.7+0.5 −2.6 R☉ |
| Luminosity | 267±6 L☉ |
| Surface gravity (log g) | 1.91 cgs |
| Temperature | 4,080+173 −30 K |
| Metallicity [Fe/H] | −0.21 dex |
| Other designations | |
| Database references | |
| SIMBAD | data |
This is an aging giant star with a stellar classification of K3 III, which indicates it has exhausted the hydrogen at its core and evolved away from the main sequence. As a consequence, it has expanded to 33 times the radius of the Sun. The star is radiating 267 times the luminosity of the Sun from its swollen photosphere at an effective temperature of 4,080 K.