Messier 48 (NGC 2548)
is a 5.8 magnitude bright open star cluster in the constellation of the Water
Snake Hydra), visible to the naked eye under good atmospheric conditions. The
apparent size of the object is about 1 degree. The age of the star cluster is
estimated to be 300 million years.
It contains stars between 9th and 13th magnitude, is located about
1,500 light years away from the solar system and is classified as class I 2 m
according to Trumpler. It was discovered on 19 February 1771 by Charles
our series of photographs the asteroid Helio stood near the star cluster.
Images of Helio are shown here ...