M 13 – Globular Cluster

The Great Globular Cluster in Hercules, also known as Messier 13 (M13) or NGC 6205, is one of the most famous and spectacular star

clusters in the northern sky. Unlike the Pinwheel Galaxy (M101), which is a sprawling collection of stars, M13 is a dense, spherical swarm of ancient stars orbiting our own Milky Way galaxy. M13 is located in the constellation Hercules and is best viewed from the Northern Hemisphere during spring and summer.

M13 contains between 300,000 and 500,000 stars. The stars at its centre are roughly 100 times more densely packed than those in our solar neighbourhood.
It is one of the oldest known objects in the universe, with an estimated age of 11.6 to 14 billion years. Size and Distance: The cluster is approximately 145 to 165 light-years in diameter and sits about 22,000 to 25,000 light-years away from Earth. M13 is incredibly bright, shining with a total luminosity more than 300,000 times that of our Sun.

Blue Stragglers: Despite its ancient age, M13 contains “blue stragglers”—stars that appear younger and bluer than they should. These are thought to form when old stars in the crowded core collide and merge. In 1974, the Arecibo radio telescope beamed a message toward M13 that contained information about humanity, DNA, and our position in the solar system, as a demonstration of human technology.