Hydra
Hya
Rank: #1
1303 sq. deg.
Hydra is the largest of the 88 modern constellations, measuring 1303 square degrees, and also the longest at over 100 degrees. Its southern end borders Libra and Centaurus and its northern end borders Cancer. It was included among the 48 constellations listed by the 2nd century astronomer Ptolemy.
IAU constellation map showing the boundaries and main stars
Hydra
| Genitive | Hydrae |
| Symbolism | the Hydra |
| Right ascension | 10h 00m 00s |
| Declination | -20° 00' 00" |
| Area | 1303 sq. deg. |
| Area rank | 1st |
| Brightest star | Alphard (mag 1.98) |
Deep-Sky Objects Summary
33
Brightest Stars
1
Open Clusters
2
Globular Clusters
31
Galaxies
0
Nebulae
Brightest Stars
| Designation | Name | Apparent magnitude | Right ascension | Declination | Spectral type |
|---|
Globular Clusters
| Designation | Name | Apparent magnitude | Right ascension | Declination | Angular size |
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Galaxies
| Designation | Name | Apparent magnitude | Right ascension | Declination | Type |
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