The Hydra constellation
Hya · Catalogue stars: 44
Why this name?
Hydra is a water snake. One Greek interpretation connects it with the Lernaean Hydra defeated by Heracles; another links it to the story of Apollo’s Crow and Cup.
A little history
This long figure has been known since antiquity and was described by Ptolemy. Modern Hydra covers the largest area of any of the 88 official constellations.
Data
- IAU code
- Hya
- Catalogue stars
- 44
- Messier objects
- 3
- Brightest star
- Alphard · 2.0ᵐ
Messier objects
Stars
Stars (HIP)
- HIP 64962 · 3.0ᵐ · G8III
- HIP 43813 · 3.1ᵐ · G8III-IV
- HIP 52943 · 3.1ᵐ · K0/K1III
- HIP 68895 · 3.3ᵐ · K2III
- HIP 56343 · 3.5ᵐ · G8III
- HIP 49841 · 3.6ᵐ · K0III
- HIP 51069 · 3.8ᵐ · K4III
- HIP 45336 · 3.9ᵐ · B9.5V
- HIP 41307 · 3.9ᵐ · A0V
- HIP 42313 · 4.1ᵐ · A1Vnn
- HIP 57936 · 4.3ᵐ · Ap Si
- HIP 42799 · 4.3ᵐ · B3V...
- HIP 43067 · 4.3ᵐ · G8III
- HIP 43234 · 4.3ᵐ · A0Vn
- HIP 72571 · 4.4ᵐ · K3III
- HIP 46776 · 4.5ᵐ · A3V
- HIP 46509 · 4.6ᵐ · F6V
- HIP 49402 · 4.6ᵐ · B8V
- HIP 42835 · 4.6ᵐ · G2Ib
- HIP 47310 · 4.7ᵐ · K3III
Altitude above the horizon by latitude
| Latitude | Maximum altitude | Rise azimuth |
|---|---|---|
| +60° | 16° | 119° |
| +55° | 21° | 115° |
| +45° | 31° | 110° |
| +30° | 46° | 106° |
| 0° | 76° | 104° |
| −35° | 69° | 107° |
Geometric altitude at upper culmination, atmospheric refraction not included. Positive latitudes are in the northern hemisphere.
Culmination time by month
| Month | Culmination |
|---|---|
| January | 02:30 |
| February | 00:22 |
| March | 22:37 |
| April | 20:44 |
| May | 18:49 |
| June | 16:43 |
| July | 14:39 |
| August | 12:38 |
| September | 10:45 |
| October | 08:57 |
| November | 06:56 |
| December | 04:47 |
Upper culmination in local solar time — no time-zone or daylight-saving correction applied.
Neighbouring constellations
In brief
Which is the brightest star in Hydra?
Alphard — 2.0ᵐ.