Magnitude 3.91 Apparent magnitude (V) 3.91 | Constellation Hydra | |
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Iota Hydrae (ι Hya) is a star in the constellation Hydra, about 8° to the north-northwest of Alphard and just to the south of the celestial equator. Visible to the naked eye, it is a suspected variable star with an apparent visual magnitude that ranges between 3.87 and 3.91. Based upon an annual parallax shift of 12.39 mas, it is located around 263 light years from the Sun.
This is an evolved K-type giant star with a stellar classification of K2.5 III. It is a Barium star, which means that, for a giant star, it displays unusually strong absorption lines of singly-ionized barium and strontium. Iota Hydrae has nearly twice the mass of the Sun and has expanded to 33 times the Sun's radius. It is around 2.5 billion years old and is spinning with a leisurely projected rotational velocity of 4.5 km/s. It may be a member of the Wolf 630 moving group of stars that share a common trajectory through space.