Messier 48 or M48, also known as NGC 2548, is a bright open cluster of stars. It is located in the equatorial constellation of Hydra. It is located near Hydra’s westernmost limit with Monoceros. The location is about 18° 34′ to the east and slightly south of Hydra’s brightest star, Alphard.
The cluster contains roughly 80 to 165 stars, with about 50 stars brighter than magnitude 13. Its population includes three yellow giant stars.
It is estimated to be around 300 to 450 million years old. This makes it an intermediate-age cluster, younger than the Hyades but older than the Pleiades.
The number of very bright blue giant stars intrigues me. This forms a contrast with a few yellow giants.
