Messier 55 (M55) - The Specter Cluster
This is a globular cluster located in the southern part of the constellation Sagittarius. It sits about 17,600 light-years away from us and contains around 269,000 solar masses. Its estimated age is around 12.3 billion years which makes is very old. As with most older clusters it is low on metal content
(low metallacity)
 
Image processed by Ron Yelton, original data from Telescope Live

                                  Location: El Sauce Observatory, Chile
                                  Date: September
                                  Mount: Mathis MI-1000
                                  Telescope: Planewave CDK24 f/6.6
                                  Camera: FLI PL9000 @ -25c  (CHI-1)
       Exposure: LRGB combined 5 min and 10 min subs - Total: 9hrs  15 min