Abbreviation: Â Hya
English Name: Â The Water Snake
Genitive:Â Alphard
Hemisphere:  Northern / Southern Hemisphere (Underlined means the more area in square feet in Southern Hemisphere.)
Location:Â Between the constellations of Crater and Antilia.
Visible between latitudes: Â +60 and -90 degrees
Best season: Spring
Seen in three seasons:Â Winter, Spring and Summer
Best seen in:Â April
Seen between:Â February and May
Right Ascension (RA):Â 10 hour
Declination (DEC):Â -20 degrees
Area (square degrees): Â 1,303 (1st)
Hydra (The Water Snake)
- Hydra is the largest of the 88 constellations in the northern and southern sky, measuring 1,303 square degrees; its head, formed by a loop of six stars between magnitude +3.0 and +4.0, lies just north of the Celestial Equator. The head of Water Snake is under the constellation of Cancer (The Crab).
- It should not be confused with the similarly named constellation of Hydrus.
Messier Objects
- M48  –  Open Cluster; visible to the naked eye under good conditions.
- M68 Â – Â Globular Cluster; wonderful challenging object for naked-eye detection.
- M83 Â – Â Barred spiral galaxy; also known as the Southern Pinwheel – one of the closest and brightest barred spiral galaxies in the sky, making it visible with binoculars. (Six supernovae have been observed in M83.)
Features of Interest
- NGC 3242 Â – Â Planetary Nebula; also commonly known as the Ghost of Jupiter; very high surface brightness and a bluish colour. (See the Video.)
Named Stars
- Alphard (Alpha Hya) – Orange giant star of magnitude +2.0. (Its traditional name means “the solitary one”.)
- Al Minliar al Shuja (Sigma Hya)
Others
- Photo of the constellation;Â Hydra, as it appears to the naked eye. (Lines have been added for clarity.)
- Sky Chart  –  Hydra
- List of stars in Hydra.
Back to The 88 Constellations Lists page.