Hydra constellation
Latin Hydra, genitive Hydrae, abbreviation Hya
North up, east to the left, as you see the sky. The lines are a common figure; the stars are from the catalogue.
The myth
The Hydra, which grew two heads whenever Heracles cut one off. The largest constellation in the sky, longer than a quarter of the horizon, but faint. Its head lies below Cancer, its heart is the lonely, reddish Alphard, 'the solitary one'.
When can Hydra be seen?
It stands highest around 10 pm in March. It can be seen from everywhere south of 70°N.
The brightest stars
| Star | Designation | Magnitude | Colour |
|---|---|---|---|
| Alphard | α Hya | 1.98 | reddish |
| – | γ Hya | 3.00 | yellow |
| – | ζ Hya | 3.11 | orange |
| – | ν Hya | 3.11 | orange |
| – | π Hya | 3.27 | orange |
| Ashlesha | ε Hya | 3.38 | yellow |
| – | ξ Hya | 3.54 | yellow |
| – | λ Hya | 3.61 | orange |
The smaller the number, the brighter: below 1 are the brightest stars of the sky, 4 is hard to see under a city sky. Greek letters after Johann Bayer (1603).