Messier 3 is one of the largest and brightest globular clusters visible from Earth. Located 33,900 light-years away in the constellation Canes Venatici, this ancient ball of stars contains an estimated 500,000 suns packed into a sphere roughly 180 light-years across.
Equipment
- Telescope: Orion 8″ 1000mm f/4.9 Newtonian reflector
- Mount: Orion Atlas EQ-G
- Imaging Camera: Canon T3i (full spectrum modification)
- Guide Scope: Meade 800mm f/10 reduced to f/5 with Atik x.5 focal reducer
- Guide Camera: Meade DSI Pro monochrome 16-bit
Capture Details
- Integration: 63 x 180sec exposures (3.15 hours total)
- Captured: Across two nights in February 2026
- Software: N.I.N.A 3.1 for capture, Siril 1.4.0 for stacking
- Resolution: 5100 x 3374 pixels
About This Object
Globular clusters like M3 are some of the oldest objects in the universe — this one is estimated to be over 11 billion years old. The stars here are packed so densely that in the core, stars are separated by only a fraction of a light-year.
M3 is a fantastic target for amateur astrophotographers because it’s bright (magnitude 6.2) and resolves well even with modest equipment. The individual stars are visible across the entire cluster, showing its spherical structure beautifully.
This image was captured from my backyard in Tennessee over two nights in February 2026.
