Iota Hydrae
Star in the constellation Hydra / From Wikipedia, the free encyclopedia
Iota Hydrae (ι Hydrae, abbreviated Iota Hya, ι Hya), formally named Ukdah /ˈʌkdə/,[7] is a star in the constellation of Hydra, about 8° to the north-northwest of Alphard (Alpha Hydrae)[8] and just to the south of the celestial equator.[9] Visible to the naked eye, it is a suspected variable star with an apparent visual magnitude that ranges between 3.87 and 3.91.[3] Based upon an annual parallax shift of 12.39 mas measured during the Hipparcos mission,[1] it is located around 263 light-years from the Sun.
Quick Facts Constellation, Right ascension ...
Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
---|---|
Constellation | Hydra |
Right ascension | 09h 39m 51.36145s[1] |
Declination | −01° 08′ 34.1135″[1] |
Apparent magnitude (V) | 3.91[2] |
Characteristics | |
Spectral type | K2.5 III[2] |
B−V color index | 1.32 |
Variable type | Suspected[3] |
Astrometry | |
Radial velocity (Rv) | +24.19±0.36[4] km/s |
Proper motion (μ) | RA: +46.96[1] mas/yr Dec.: −62.39[1] mas/yr |
Parallax (π) | 12.39 ± 0.14 mas[1] |
Distance | 263 ± 3 ly (80.7 ± 0.9 pc) |
Absolute magnitude (MV) | −0.63[5] |
Details | |
Mass | 1.92[2] M☉ |
Radius | 33[4] R☉ |
Luminosity | 83[2] L☉ |
Surface gravity (log g) | 2.2[4] cgs |
Temperature | 4,244±32[2] K |
Metallicity [Fe/H] | −0.05[2] dex |
Rotational velocity (v sin i) | 4.5[4] km/s |
Age | 2.47[2] Gyr |
Other designations | |
Database references | |
SIMBAD | data |
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