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
Ukdah, ι Hya, 35 Hydrae, BD−00° 2231, FK5 1250, HD 83618, HIP 47431, HR 3845, SAO 137035.[6]
Database references
SIMBAD
data
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.
^ abcdefCite error: The named reference vanLeeuwen2007 was invoked but never defined (see the help page).
^ abcdefgCite error: The named reference Luck2015 was invoked but never defined (see the help page).
^ abCite error: The named reference gcvs2009 was invoked but never defined (see the help page).
^ abcdCite error: The named reference Massarotti2008 was invoked but never defined (see the help page).
^Cite error: The named reference Anderson2012 was invoked but never defined (see the help page).
^Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
^"Naming Stars". IAU.org. Retrieved 18 June 2018.
^Cite error: The named reference OMeara2007 was invoked but never defined (see the help page).
^Cite error: The named reference Moore2013 was invoked but never defined (see the help page).
IotaHydrae (ι Hydrae, abbreviated Iota Hya, ι Hya), formally named Ukdah /ˈʌkdə/, is a star in the constellation of Hydra, about 8° to the north-northwest...
is located in the sky about 2 and a half degrees south-south east of IotaHydrae and more than 6 degrees northeast of Alphard. A 10th magnitude star lies...
Geminorum Triple star system 3.54 Iota Cephei Star 3.54 Xi Hydrae Star 3.54 Delta Eridani Star Suspected variable star 3.54 Iota Lupi Star Maximum brightness...
see it in a few of the several thousand Mira stars known, possibly in R Hydrae. Most Mira variables do exhibit slight cycle-to-cycle changes in period...
1889 1889 Mato Grosso do Sul Alpha Hydrae (Alphard) Hydra, the Water Serpent 2 1979[note] 1960[note] Acre Gamma Hydrae Hydra, the Water Serpent 3 1962 1968...
النِّطَاق Zeta Orionis Alphard al-Fard the Solitary one الفرد الفَرْد Alpha Hydrae Alphecca (Nayyir) al-Fakkah (the Bright one of) the Broken (Ring) نير الفكة...
time TTS – (celestial object) T-Tauri star TWA – (celestial object) TW Hydrae Association TYC – (catalog) Tycho, a catalog that was the predecessor of...