Messier 48 (also known as M 48 or NGC 2548) is an open cluster in the Hydra constellation. It was discovered by Charles Messier in 1771.
There is no cluster in the position indicated by Messier. The value that he gave for the right ascension matches that of NGC 2548, however, his declination is off by five degrees. Credit for discovery is sometimes given instead to Caroline Herschel in 1783.
M48 is visible to the naked eye under good atmospheric conditions. Its age is estimated to amount 300 million years.