Globular Cluster M3

Messier 3 (also known as M3 or NGC 5272) is a globular cluster of stars. This cluster is one of the largest and brightest, and is made up of around 500,000 stars. It is estimated to be 8 billion years old.

Messier 3 is located Template:Convert above the Galactic plane and roughly Template:Convert from the center of the Milky Way. It contains 274 known variable stars. The overall abundance of elements other than hydrogen and helium, known as metallicity, is in the range of –1.34 to –1.50 dex. This value gives the logarithm of the abundance relative to the Sun; the actual proportion is 3.2–4.6% of the solar abundance. Messier 3 is the prototype for the Oosterhoff type I cluster, which is considered "metal-rich". That is, for a globular cluster, Messier 3 has a relatively high abundance of heavier elements.