Sigma Hydrae
Sigma Hydrae (σ Hydrae, abbreviated Sigma Hya, σ Hya), also named Minchir /ˈmɪŋkər/, is a solitary star in the equatorial constellation of Hydra. It is visible to the naked eye with an apparent visual magnitude of 4.48. The estimated distance to this star from the Sun, based upon an annual parallax shift of 8.75 mas, is around 370 light-years. At that distance, the visual magnitude of the star is diminished by an interstellar extinction factor of 0.16, due to intervening dust.
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Hydra |
| Right ascension | 08h 38m 45.43747s |
| Declination | +03° 20′ 29.1701″ |
| Apparent magnitude (V) | 4.48 |
| Characteristics | |
| Spectral type | K2 III |
| U−B color index | +1.23 |
| B−V color index | +1.21 |
| Astrometry | |
| Radial velocity (Rv) | 27.28±0.19 km/s |
| Proper motion (μ) | RA: −19.48 mas/yr Dec.: −15.92 mas/yr |
| Parallax (π) | 8.75 ± 0.25 mas |
| Distance | 370 ± 10 ly (114 ± 3 pc) |
| Absolute magnitude (MV) | −0.84 |
| Details | |
| Mass | 3.07 M☉ |
| Radius | 27.6 R☉ |
| Luminosity | 295 L☉ |
| Surface gravity (log g) | 2.21±0.13 cgs |
| Temperature | 4,491±51 K |
| Metallicity [Fe/H] | 0.13±0.06 dex |
| Age | 430 Myr |
| Other designations | |
| Database references | |
| SIMBAD | data |
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