Messier 05 is a Globular Cluster located in the constellation of Serpens Caput (the Snake Head), and makes for fine viewing with the mix of orange and blue stars and pairs well with the bright star 5 Serpentis. The cluster is comprised of over 100,000 stars and is located approximately 25,000 light years away from Earth. Whilst we can see 5 Serpentis in the same field of view as the cluster, the star is only 83 light years away so is much closer to Earth.

The bright star that can be seen in the field of view, 5 Serpentis, is a binary star. The primary component (5 Ser A) has a visual magnitude of 5.1 whilst its companion (5 Ser B) has a magnitude of 10.1 and is separated by 11.4 arc seconds. Whilst it might be tempting to conclude that the small orange star adjacent to 5 Serpentis in the image is its binary companion, this is not the case. I used the Stellarium planetarium program to measure the angular separation between these two stars in the image and the separation is 34 arc seconds. The actual binary companion is buried in the glow from the primary star.