Epoch J2000.0 Equinox J2000.0
|Right ascension||8h 37m 39.4s|
|Declination||5° 42′ 13″|
|Apparent magnitude (V)||4.14|
Delta Hydrae (δ Hya, δ Hydrae) is a Class A1, fourth-magnitude star in the constellation Hydra. Delta Hydrae is a binary double star, located about 180 light-years from Earth. It has 2.2 times the mass of the Sun, 1.5 times the Sun's radius and is radiating 17 times the luminosity of the Sun.
Name and etymology
In the catalogue of stars in the Calendarium of Al Achsasi Al Mouakket, this star was designated Lisan al Shudja, which was translated into Latin as Lingua Hydri, meaning the snake's tongue. This star, along with ε Hya, ζ Hya, η Hya, ρ Hya and σ Hya (Minhar al Shija), were Ulugh Beg's Min al Azʽal, "Belonging to the Uninhabited Spot".
According to the catalogue of stars in the Technical Memorandum 33-507 - A Reduced Star Catalog Containing 537 Named Stars, Min al Azʽal or Minazal were the title for five stars :δ Hya as Minazal I, η Hya as Minazal II, ε Hya as Minazal III, ρ Hya as Minazal IV and ζ Hya as Minazal V (exclude σ Hya)
In Chinese, 柳宿 (Liǔ Sù), meaning Willow (asterism), refers to an asterism consisting of δ Hydrae, σ Hydrae, η Hydrae, ρ Hydrae, ε Hydrae, ζ Hydrae, ω Hydrae and θ Hydrae Consequently, δ Hydrae itself is known as 柳宿一 (Liǔ Sù yī, English: the First Star of Willow.)
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