AAO image reference AAT 116. « Previous || Next »
Top left is NE. Image width is about 25 arc min
Image and text © 2000-2010, Australian Astronomical Observatory, photograph by David Malin.
This splendid cluster of galaxies in Hydra is framed by two nearby, cool stars in our own Milky Way. The brightest is about 5th magnitude, visible to the unaided eye only under a dark sky; the second brightest is below naked-eye visibility. In contrast the galaxies appear featureless in all but the largest telescopes. The bluish, elongated galaxy is an edge-on spiral, NGC 3312. It has been distorted by interactions with its neighbours. They in turn have been affected, and the brightest of the two adjacent yellow elliptical galaxies (NGC 3311) has an assymetrical envelope, perhaps as a result of this encounter. It's hard to tell who is jostling who in a crowded group of galaxies such as this.
Among the most interesting galaxies in the group are two faint spirals (NGC 3314) that are by chance aligned along the line of sight. They are seen a little to the left of the fainter star and directly below the brighter. On a higher resolution AAT picture it is clear we are seeing one galaxy in front of another. These galaxies are even better seen in a beautiful HST image. Such chance alignments are rare and allow astronomers to study the contents of the foreground galaxy in great detail, thus addressing a controversial topic in astronomy: are galaxies transparent?
For details of photographic exposure, search technical table by AAT reference number.
| emission nebulae
| reflection nebulae
| dark nebulae
| planetary nebulae
| star clusters
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