| HYDRA Chart | Midnight Culmination | Skylore | Description | Star Clusters |
| Galaxies | Discussed in these Shows |

Constellation Data

  • Name: HYDRA
  • Translation: Sea serpent
  • Abbreviation: Hya
  • Genitive: Hydrae
  • Size: 1
  • RA: 11 hours
  • Decl: -15 degrees
  • Season: Spring
  • Midnight Culmination: March 15
  • Pages where HYDRA is discussed in Chet Raymo's 365 Starry Nights: 38,43,52,53

What is the Genitive form?
What is Right Ascension (RA)?
Is this constellation ever visible from my latitude? What is Declination?

Where should I look for a constellation on a date before or after its midnight culmination? What is Midnight Culmination?


Hercules was sent to kill Hydra, a sea monster which possessed the terrifying ability, whenever a head was cut off, to grow two heads in its place.

Cicero, De natura deorum, II.110, trans. of Phenomena by Aratos of Soli (ca. 220 B.C.):
Here Hydra rises from the nether realms,
And in her midmost coil the Wine-bowl (Crater) gleams,
While pressing at her tail the feathered Crow (Corvus)
Pecks with his beak; and here, hard by the Twins,
The Hound's forerunner, in Greek named Prokyon.


The largest and longest of the constellations, stretching from Cancer to Libra. Its brightest star is Alphard, with an orangish tint. Two constellations ride it, Crater (cup) and Corvus (crow).

[star chart]

Star chart created with Voyager II Software for Macintosh, published by Carina Software. This is just a taste of what Voyager can do! For info on Voyager II software, call Carina Software at (510) 355-1266, write them at 12919 Alcosta Blvd Suite #7, San Ramon, CA 94583, or visit Carina Software's home page and check out Voyager II for yourself.

Star Clusters

M48 (Galactic cluster), mag. 6.0.

M68 (Globular cluster), mag. 8.2.

What are Star Clusters?


M83 (Spiral galaxy), mag. 7.6.

What are Galaxies?
Table of Messier Objects.
What is apparent Magnitude?

Discussed in these Shows

[Small Logo] ©1997 Welcome to the Basic Celestial Phenomena web site. To provide explanations of basic observational astronomy to students, teachers, families, and visitors to planetariums these pages have been written by an ex-OBU Planetarium Director, Kerry Magruder; the OBU Natural Sciences Coordinator, Mike Keas; and some of the students who work in the OBU planetarium.

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