Constellation · Hya
Hydra
The Water Snake
The largest of the 88 constellations by area; it stretches more than a quarter of the way around the sky and has a single bright star, Alphard.
Magnitude 1.99
Highest in the sky at 9 pm local time (spring in the northern hemisphere)
Latitudes where every part of it rises above the horizon at some time of year
The whole sky covers about 41,253 square degrees
Stars brighter than about magnitude 6, the naked-eye limit under dark skies
Named stars in Hydra
Brightest first. A lower magnitude means a brighter star.
- Alphard (Alpha Hydrae)mag 1.99
- Ashlesha (Epsilon Hydrae)mag 3.38
- Ukdah (Iota Hydrae)mag 3.90
- Zhang (Upsilon¹ Hydrae)mag 4.11
- Minazal (Delta Hydrae)mag 4.14
- Minchir (Sigma Hydrae)mag 4.45
Can you see Hydra from where you live?
This depends only on your latitude. Pick the row nearest to you; for your exact sky tonight, use the sky map.
| Latitude | Hydra |
|---|---|
| 60°N | Only part of it ever clears the horizon |
| 40°N | The whole constellation rises and sets |
| 20°N | The whole constellation rises and sets |
| the equator | The whole constellation rises and sets |
| 20°S | The whole constellation rises and sets |
| 40°S | The whole constellation rises and sets |
| 60°S | The whole constellation rises and sets |
Questions about Hydra
When is Hydra best seen?
Hydra stands highest in the sky at 9 pm local time in April. That makes spring evenings the best time for observers in the northern hemisphere; in the southern hemisphere the season is reversed.
What is the brightest star in Hydra?
The brightest star in Hydra is Alphard (Alpha Hydrae), magnitude 1.99.
Where on Earth can you see Hydra?
The whole of Hydra can be seen from latitudes between about 83°S and 54°N. From 40°N: The whole constellation rises and sets. From 35°S: The whole constellation rises and sets.
What does Hydra mean?
Hydra is Latin for "the Water Snake". One of Ptolemy's 48 ancient constellations (2nd century).