M3 - Globular Cluster
M3 is one of the finest globular clusters in the northern sky, containing approximately 500,000 stars. It's considered one of the best test objects for telescopes due to its concentration.
Distance: 33,900 light-years
Apparent Magnitude: 6.20
Apparent Size: 18'
Constellation: Canes Venatici
Object Type: Globular Cluster (Class VI)
Key Features:
- ~500,000 member stars
- Contains 274 variable stars (most of any cluster)
- Age: 11.4 billion years
- 12 billion solar masses
- Discovered by Messier in 1764
Best Imaging Season: March - July
Optimal Integration: 3+ hours
