Hydra constellation
Hydra is one of the 88 constellations, and it represents the water snake. It is highest in the sky at midnight around February 20, 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
- February 20
- Highest at 9 pm
- April 6
- 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 February 20 and at 9 pm around April 6. 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 |
|---|---|
| January 15 | 2:20 AM |
| February 15 | 12:20 AM |
| March 15 | 10:30 PM |
| April 15 | 8:20 PM |
| May 15 | 6:30 PM |
| June 15 | 4:20 PM |
| July 15 | 2:30 PM |
| August 15 | 12:20 PM |
| September 15 | 10:20 AM |
| October 15 | 8:20 AM |
| November 15 | 6:20 AM |
| December 15 | 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 February 20, 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 February 20, 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 February 20 and at 9 pm around April 6. 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.