At the age of 38, in 1665 the German amateur astronomer Johann Abraham Ihle, one night observing Saturn, observed cloud-like spots near Saturn, which was approximately 1° and 40’ away. This was the first globular cluster reported in history.
It is a very bright cluster, located in the constellation of Sagittarius, with an approximate magnitude of 5.1 being the third brightest cluster in the sky, second only to Omega Centauri and 47 Tucanae.
In 1986, the IRAS satellite discovered a feature, quite unusual among clusters, the presence of a planetary nebula, only four known globular clusters contain planetary nebulae, the other three being Messier 15, NGC 6441 and Palomar 6.
Two black holes were discovered in M22 and confirmed by the Chandra X-ray telescope in 2012, designated M22-VLA1 and M22-VLA2, but are believed to have others.
Best details(takes a while to open because the image is gigantic):
https://www.astrobin.com/full/tzqre4/E/
EQUIPMENT:
ZWO ASI 6200MC PRO COLED
Espirit 150mm
55x100s
Date: . 07/10/2021
Location: Jales-SP-Brazil
Copyright: Fernando Oliveira de Menezes
Email: Barretosmed@hotmail.com