Messier 3 (also known as M3 or NGC 5272) is a globular cluster in the constellation Canes Venatici. This cluster is one of the largest and brightest, and is made up of around 500,000 stars. It is located at a distance of about 33,900 light-years away from Earth. M3 has an apparent magnitude of 6.2, making it visible to the naked eye under dark conditions. From a moderate-sized telescope, the cluster is fully defined. [Wikipedia]