M13 “Hercules Globular Cluster”May 17, 2020
M13 was the second object to be taken with the observatory instrumentation that, at the time was the same of the previous image NGC891. Even for this picture the exposition data are unknown, perhaps about 10 frames of 300 seconds.
Messier 13 or M13, also designated NGC 6205 and sometimes called the Great Globular Cluster in Hercules or the Hercules Globular Cluster, is a globular cluster of several hundred thousand stars in the constellation of Hercules.
M13 was discovered by Edmond Halley in 1714, and cataloged by Charles Messier on June 1, 1764 into his list of objects not to mistake for comets; Messier’s list, including Messier 13, eventually became known as the Messier Catalog.