Messier 3 (M3 or NGC 5272) is a globular cluster of stars in the northern constellation of Canes Venatici. It was discovered by Messier on May 3, 1764, and resolved into stars by William Herschel around 1784. It has an unusually large variable star population and new variable members continue to be identified up through.
The brightest and largest globular cluster in the Milky Way, containing as many as 10 million stars
The globular cluster is found in the constellation Centaurus, in the Southern Hemisphere.
It is 16,000 light-years from earth.