Hydra (astronomy)

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Hydra

Hydra in astronomy, southern constellation lying S of Corvus, Crater, Virgo, Leo, and Cancer. It is a long, slender, winding constellation traditionally depicted as a snake and known also as the Water Monster or Sea Serpent. The only bright star in the constellation is Alphard (Alpha Hydrae); it is a double star, but the two components can be detected only with a telescope. Hydra reaches its highest point in the evening sky in the spring.

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Hydra

World Encyclopedia | 2005 | Â© World Encyclopedia 2005, originally published by Oxford University Press 2005. (Hide copyright information) Copyright

Hydra Largest constellation in the sky. It represents the water snake killed by Heracles in classical mythology.

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Hydra

A Dictionary of Astronomy | 1997 | Â© A Dictionary of Astronomy 1997, originally published by Oxford University Press 1997. (Hide copyright information) Copyright

Hydra (abbr. Hya, gen. Hydrae) The largest constellation of all, representing a water-snake. Hydra meanders from the celestial equator into the southern celestial hemisphere, and is over 100° long. Its brightest star is Alphard (Alpha Hydrae). R Hydrae is a Mira star that varies between magnitudes 4 and 11 every 390 days, and U Hydrae is a semiregular variable that ranges between magnitudes 4.3 and 6.5. M48 is a 6th-magnitude open star cluster visible in binoculars, and M83 is an 8th-magnitude spiral galaxy. NGC 3242 is a planetary nebula known as the Ghost of Jupiter.

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