Credits: Jim Misti (Image Acquisition), Aldo Zanetti (Processing)
ronomical and Imaging Data
| RA: | 13h 42m 11.62s |
| DEC: | +28° 22′ 38.2″ |
| MAG: | 6.19 |
| Diameter: | 18′ |
| Const: | CVn |
| OTA | OGS 32″ RC |
| Focal Length | 6000 |
| Camera | SBIG STL-11000M |
| Site | Arizona, USA |
| Sky Quality | Bortle 2 |
Useful Informations
NGC 5272, also known as Messier 3 (M3), is one of the brightest and most well-studied globular clusters in the Northern Hemisphere. Located in the constellation Canes Venatici, it’s an exceptionally old and metal-poor stellar system.
Physical and Chemical Properties
M3 is approximately 33,900 light-years away from Earth and is home to an estimated half-million stars. Its immense size and stellar population make it one of the largest and most massive globular clusters known. It’s classified as a Shapley-Sawyer Concentration Class VI, indicating a moderate level of central concentration.
- Age and Metallicity: With an age of around 11.4 billion years, M3 is an ancient relic of the early universe. Its stars are very metal-poor, with an abundance of heavy elements ([Fe/H]) about 200 times lower than that of our Sun. This low metallicity is consistent with its formation from pristine, unenriched gas clouds.
- Structure and Dynamics: The cluster has a low core-collapse ratio, meaning its central region is not as extremely dense as some other globular clusters. This provides an excellent opportunity to study stellar dynamics in a less chaotic environment.
Notable Features and Scientific Significance
M3 is a premier laboratory for understanding stellar evolution and the properties of variable stars.
- Variable Stars: The cluster contains an exceptionally rich population of variable stars, with over 200 identified, including a large number of RR Lyrae stars. This makes M3 a critical object for testing theories of stellar pulsation and for calibrating the cosmic distance scale.
- Blue Stragglers: M3 hosts a significant population of blue straggler stars, which are thought to be the result of stellar collisions or mergers in the dense cluster environment. Their presence provides important clues about the dynamical processes at work within the cluster.
- Galactic Accretion: Recent studies of M3’s proper motion suggest it might be part of the Virgo Stream, a large stream of stars in the galactic halo. This connection hints that M3 could be a former member of a dwarf galaxy that was gravitationally stripped and accreted by the Milky Way.