Delta Hydrae
Encyclopedia
Delta Hydrae is a Class A1
Stellar classification
In astronomy, stellar classification is a classification of stars based on their spectral characteristics. The spectral class of a star is a designated class of a star describing the ionization of its chromosphere, what atomic excitations are most prominent in the light, giving an objective measure...

, fourth-magnitude star
Star
A star is a massive, luminous sphere of plasma held together by gravity. At the end of its lifetime, a star can also contain a proportion of degenerate matter. The nearest star to Earth is the Sun, which is the source of most of the energy on Earth...

 in the constellation
Constellation
In modern astronomy, a constellation is an internationally defined area of the celestial sphere. These areas are grouped around asterisms, patterns formed by prominent stars within apparent proximity to one another on Earth's night sky....

 Hydra
Hydra (constellation)
Hydra is the largest of the 88 modern constellations, measuring 1303 square degrees. It has a long history, having been included among the 48 constellations listed by the 2nd century astronomer Ptolemy. It is commonly represented as a water snake...

. Delta Hydrae is a binary double star, located about 180 light-year
Light-year
A light-year, also light year or lightyear is a unit of length, equal to just under 10 trillion kilometres...

s from Earth.

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
Latin
Latin is an Italic language originally spoken in Latium and Ancient Rome. It, along with most European languages, is a descendant of the ancient Proto-Indo-European language. Although it is considered a dead language, a number of scholars and members of the Christian clergy speak it fluently, and...

 as Lingua Hydri, meaning the snake's tongue.
This star, along with ε Hya
Epsilon Hydrae
Epsilon Hydrae is a Class G5, third-magnitude star in the constellation Hydra. Epsilon Hydrae is a binary star with components of magnitudes 3.3 and 6.8, separated by 2.7 arcseconds...

, ζ Hya
Zeta Hydrae
Zeta Hydrae is a Class G9, third-magnitude star in the constellation Hydra. Zeta Hydrae is a yellow giant star located about 150 light-years from Earth.-Name and etymology:...

, η Hya, ρ Hya and σ Hya
Sigma Hydrae
Sigma Hydrae is the 4th-magnitude star in the constellation Hydra. Sigma Hydrae belongs to spectral class K1+III and has apparent magnitude +4.44...

 (Minhar al Shija), were Ulugh Beg
Ulugh Beg
Ulugh Bek was a Timurid ruler as well as an astronomer, mathematician and sultan. His commonly-known name is not truly a personal name, but rather a moniker, which can be loosely translated as "Great Ruler" or "Patriarch Ruler" and was the Turkic equivalent of Timur's Perso-Arabic title Amīr-e...

'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
Epsilon Hydrae
Epsilon Hydrae is a Class G5, third-magnitude star in the constellation Hydra. Epsilon Hydrae is a binary star with components of magnitudes 3.3 and 6.8, separated by 2.7 arcseconds...

 as Minazal III, ρ Hya as Minazal IV and ζ Hya
Zeta Hydrae
Zeta Hydrae is a Class G9, third-magnitude star in the constellation Hydra. Zeta Hydrae is a yellow giant star located about 150 light-years from Earth.-Name and etymology:...

 as Minazal V (exclude σ Hya
Sigma Hydrae
Sigma Hydrae is the 4th-magnitude star in the constellation Hydra. Sigma Hydrae belongs to spectral class K1+III and has apparent magnitude +4.44...

)

In Chinese
Chinese language
The Chinese language is a language or language family consisting of varieties which are mutually intelligible to varying degrees. Originally the indigenous languages spoken by the Han Chinese in China, it forms one of the branches of Sino-Tibetan family of languages...

, , meaning Willow
Willow (Chinese constellation)
The Willow mansion is one of the Twenty-eight mansions of the Chinese constellations. It is one of the southern mansions of the Vermilion Bird.-Asterisms:...

 (asterism)
, refers to an asterism consisting of δ Hydrae, σ Hydrae
Sigma Hydrae
Sigma Hydrae is the 4th-magnitude star in the constellation Hydra. Sigma Hydrae belongs to spectral class K1+III and has apparent magnitude +4.44...

, η Hydrae, ρ Hydrae, ε Hydrae
Epsilon Hydrae
Epsilon Hydrae is a Class G5, third-magnitude star in the constellation Hydra. Epsilon Hydrae is a binary star with components of magnitudes 3.3 and 6.8, separated by 2.7 arcseconds...

, ζ Hydrae
Zeta Hydrae
Zeta Hydrae is a Class G9, third-magnitude star in the constellation Hydra. Zeta Hydrae is a yellow giant star located about 150 light-years from Earth.-Name and etymology:...

, ω Hydrae and θ Hydrae Consequently, δ Hydrae itself is known as

The people of Groote Eylandt
Groote Eylandt
Groote Eylandt is the largest island in the Gulf of Carpentaria in northeastern Australia. It is the homeland of, and is owned by, the Anindilyakwa people who speak the isolated Anindilyakwa language)....

 called Unwala, "The Crab", for the star cluster including this star, ε Hya
Epsilon Hydrae
Epsilon Hydrae is a Class G5, third-magnitude star in the constellation Hydra. Epsilon Hydrae is a binary star with components of magnitudes 3.3 and 6.8, separated by 2.7 arcseconds...

, ζ Hya
Zeta Hydrae
Zeta Hydrae is a Class G9, third-magnitude star in the constellation Hydra. Zeta Hydrae is a yellow giant star located about 150 light-years from Earth.-Name and etymology:...

, η Hya, ρ Hya and σ Hya
Sigma Hydrae
Sigma Hydrae is the 4th-magnitude star in the constellation Hydra. Sigma Hydrae belongs to spectral class K1+III and has apparent magnitude +4.44...

(Minhar al Shija).
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