About image
M3 is a globular cluster visible in the constellation of Canes
Venatici.
It is formed by about 500,000 stars and has a distance of about 33,900 light
years from the Earth: its apparent magnitude of 6.2 makes it visible to the
naked eye under a dark sky.
With M13 and M5, M3 is one of the three brightest globular clusters in the northern
hemisphere. This has meant that it has been studied more than other clusters of
its type, and the HR diagram resulting from these studies shows that M3 is a
cluster of extremely old stars: it is believed that they are about 10 or more
billions of years.
