Click on the image for a full resolution version   Messier 107 was discovered by Pierre Mechain in 1782, but it was not added to the Messier Catalog until 1947. This 13 arcmin wide cluster contains about 100,000 stars, having a mass of about 180,000 solar masses. Additional Information Object Name(s): Messier 107. M107. NGC … Continue reading Messier 107. NGC 6171