This wonderful cluster of galaxies in the southern constellation of Hydra is framed by two nearby cool stars in our own Milky Way, with only the brightest one of the two visible to the unaided eye under a dark sky. But while these foreground stars are only few hundreds of light-years distant, the galaxies of this cosmic city are over 100 million light-years away.
At the heart of the cluster are three large dominant galaxies, two yellow ellipticals (NGC 3311, NGC 3309) and one prominent blue edge-on spiral (NGC 3312). Each one of them is about 150,000 light-years in diameter, or about 1.5 times larger than or own milky way. Just above and left of NGC 3312 is an intriguing overlapping galaxy pair cataloged as NGC 3314. The two faint spirals are by chance aligned along our line of sight, a quite rare occurrence that allow astronomers to study the contents of the foreground galaxy in great detail as well as measuring its "transparency".
Also known as Abell 1060, the Hydra galaxy cluster is estimate to contain more than 150 galaxies and is one of three large galaxy clusters within 200 million light-years of the Milky Way. In the universe, galaxies are gravitationally bound into clusters which themselves are loosely bound into superclusters that in turn are seen to align over even larger scales.
Takahashi CCA250 (250/f5) - ZWO 6200MM - L (300m) R (60m) G (60m) B (60m) - AMT Observatory (
A.Lau/M.Lorenzi/T.Tse), Río Hurtado, Chile. Image processing M.Lorenzi.
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