M 4 is a globular cluster located in the constellation
Scorpius, seen near the bright star Antares. It is perhaps
the globular cluster closest to the earth, 7200 light years
away. It is just visible to the naked eye under very dark skies,
but would be far brighter if not for the large amount of interstellar
material between us and it. This material gives the cluster its
rather dull, yellow-brown appearance. A peculiar feature of M 4 is
the bar of fairly bright stars (in this image, running horizontally
through the core).

Image data:
Camera: Canon 350XT (modified)
Exposure: ISO 800, 1 minute x 27
Telescope: 10" Schmidt-Newtonian, Baader coma corrector