Hydra constellation
Hydra is one of the 88 constellations, and it represents the water snake. It is highest in the sky at midnight around 20 February, and its whole figure rises above the horizon from 56°N to 84°S.
Hydra at a glance
- Represents
- the water snake
- Highest at midnight
- 20 February
- Highest at 9 pm
- 6 April
- Seen whole from
- 56°N to 84°S
- Brightest star
- Alphard
- Stars in the figure
- 18 stars
- Origin
- Ptolemy's list, 2nd century
When to see Hydra
Hydra is highest in the sky at midnight around 20 February and at 9 pm around 6 April. Each month it is highest about two hours earlier than the month before.
The times are local solar time. Clocks on summer time or daylight saving time read about one hour later.
| Date | Highest at |
|---|---|
| 15 January | 2:20 am |
| 15 February | 12:20 am |
| 15 March | 10:30 pm |
| 15 April | 8:20 pm |
| 15 May | 6:30 pm |
| 15 June | 4:20 pm |
| 15 July | 2:30 pm |
| 15 August | 12:20 pm |
| 15 September | 10:20 am |
| 15 October | 8:20 am |
| 15 November | 6:20 am |
| 15 December | 4:20 am |
Where to look for Hydra
From the northern hemisphere
From 40°N, Hydra rises in the east and sets in the west. It is highest around midnight on 20 February, 41° above the southern horizon.
From the southern hemisphere
From 35°S, Hydra rises in the east and sets in the west. It is highest around midnight on 20 February, 64° above the northern horizon.
Brightest stars in Hydra
| Star | Magnitude |
|---|---|
| Alphard | 1.99 |
Hydra in myth and history
Hydra, the water snake, is the largest of the 88 constellations.
Hydra is one of the 48 constellations that the astronomer Ptolemy listed in the 2nd century.
Constellations next to Hydra
Find Hydra in your sky
Questions about Hydra
Hydra is highest in the sky at midnight around 20 February and at 9 pm around 6 April. The weeks around those dates are the best time to look.
The whole figure of Hydra rises above the horizon from 56°N to 84°S, and at least part of it rises everywhere on Earth.
Alphard is the brightest star in Hydra, at magnitude 1.99.
Hydra represents the water snake. Hydra is one of the 48 constellations that the astronomer Ptolemy listed in the 2nd century.