The Hydra Cluster of Galaxies
Image Credit & Copyright:
Rafael Sampaio
Within our own Milky Way galaxy, two bright, spiky stars stand
like sentinels
in the foreground of
this cosmic snapshot.
Far beyond them are the galaxies of
the Hydra Cluster.
In fact, while the spiky foreground stars are hundreds of light-years
distant, the Hydra Cluster
galaxies are well over 100 million light-years away.
Three large galaxies near the cluster center, two yellow
ellipticals
(NGC 3311, NGC 3309) and one prominent blue spiral (NGC 3312),
are the dominant galaxies, each about 150,000 light-years in diameter.
An intriguing overlapping galaxy pair cataloged as
NGC 3314 lies
above and left of NGC 3312.
Also known as Abell 1060, the Hydra galaxy cluster is one of three large
galaxy clusters within 200 million light-years of the Milky Way.
In the
nearby universe,
galaxies are gravitationally bound into clusters which themselves are
loosely bound
into superclusters.
Superclusters in turn are seen to align over even larger
scales.