- Messier 51 refers to the connected pair of galaxies known as Messier 51a (NGC 5194) and Messier 51b (NGC 5195). It is also known as the Whirlpool Galaxy although technically that name applies to Messier 51a rather than both.
- Messier 25 (Wikipedia)
Messier 25, also known as IC 4725, is an open cluster of stars in the southern constellation of Sagittarius. The first recorded observation of this cluster was made by Philippe Loys de Chéseaux in 1745 and it was included in Charles Messier’s list of nebulous objects in 1764. The cluster is located near some obscuring features, with a dark lane passing near the center.
