M3

Designation: M5 / NGC 5272
Hemisphere: Northern
Constellation: Canes Venatici
Distance: 34,000 light years
Object type: Globular Cluster

Description

M3 is one of the brightest globular clusters, spherical collections of stars tightly bound together by gravity. The cluster contains over 500,000 stars (of which 274 are variable stars) and sits in the constellation Canes Venatici, some 34,000 light-years away from Earth. It spans across 220 light-years and has an estimated age of 8 billion years.

M3 was the first object in the Messier catalogue to be discovered by Charles Messier himself. He spotted the cluster in 1764 although mistaking it for a nebula with no stars. It was only in 1784 that William Herschel was able to resolve the cluster’s individual stars.

North of M3 is the spiral galaxy NGC 5263, estimated to be around 222 million light years away from Earth. Click on the image below to check it out.

Equipment

Mount: Sky-watcher HEQ5-Pro
Main Telescope: William Optics ZS73EDii
Main camera: ZWO ASI294MC-Pro
Main camera filters: Optolong L-Pro
Guidescope: AstroEssential 50/200
Guide camera: ZWO ASI174MM
Guide camera filter: Astronomik UV/IR cut

Acquisition details

Total integration time: 2 hours
Acquisition software: ZWO AsiAir
Processing software: PixInsight – GIMP
Locations: Luxembourg

Full size image