The Texas Astronomical Society presents:

Constellation of the Month

by Rick Raasch


The constellation of Hydra is both the largest and longest of all the constellations, spanning almost 7 hours of Right Ascension, and covering over 1300 square degrees. The attendant constellations of Corvus, Crater, and Sextans seem to ride on the back of Hydra as it winds across the sky. While on the whole this is a rather sparse region of the sky containing primarily faint and distant galaxies, there are three Messier objects and several fine Herschel objects in the area, making the hunt worthwhile.


M-48 This is a fine open cluster over one half of a degree in diameter, and easily seen in binoculars. It is composed primarily of fairly bright stars, loosely concentrated to the center. I estimated about 75 stars in the area.

M-68 This rather bright globular cluster is about 8-10' in diameter and is very compact, showing a bright, granulated core and many stars resolved around its edges.

M-83 This is one of the finest examples of a face on barred spiral galaxies in the sky. It is large, about 10' in diameter, with an obvious central bar and spiral arms which seem to go all the way around the galaxy. Often photographed by amateurs, this is a real gem of the night sky.

NGC 3242 The Ghost of Jupiter. This is a very impressive planetary nebula, showing a blue-green disk almost 1' in diameter with a bright center and fuzzy edges. I saw a bright spot on the SE edge, and another but fainter brightening to its NW.


NGC 4038-9 The Ring Tail or Antennae Galaxy. This fascinating object is actually two interacting galaxies which have been greatly distorted by gravitational forces. A telescope shows a curving arc about 3' in length and about 2' at its widest point. Oriented N-S, it looks like a bulging crescent and is brighter on the northern end.

NGC 4361 This large planetary nebula is about 50" in diameter, and has an easily seen central star. The nebulosity is grey, and reminds me somewhat of the Owl Nebula in Ursa Major.

Stargate Anyone logging on to the Stargate BBS, run by Observing Coordinator John Wagoner will be greeted by a graphical representation of this pretty asterism along with its coordinates: Right Ascension - 12h 36m Dec - Minus 12 degrees. It seems that while John was working on his Messier Certificate, he bumped into this grouping of stars while on the way to M-104. It reminded him of the stargate used by Buck Rogers and friends to enter hyperspace, hence the name he bestowed upon it. The rest is history.


NGC 3115 The Spindle Galaxy. This striking object is bright and moderately large in size, about 6'x1' in extent. It has a sharply brighter core and a stellar nucleus. A very pretty object.

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This page was last modified: Apr. 8, 1995