Credit: Armen Akopian
Astronomical and Imaging Data
| RA: | 12h 10m 06.30s |
| DEC: | +18° 32′ 33.5″ |
| MAG: | 10.32 |
| Diameter: | 4.4′ |
| Const: | Com |
| OTA | Vixed 103ED |
| Focal Length | 800mm |
| Camera | ASI294MM |
| Site | San Antonio, TX, United States |
| Sky Quality | Bortle 7 |
Useful Informations
NGC 4147 is a globular cluster located in the constellation Coma Berenices. It’s a relatively small and faint cluster, ranking 112th in luminosity among the Milky Way’s globular clusters, with an apparent magnitude of 10.32. However, its significant distance from the Galactic Center and its unique stellar population characteristics make it a scientifically intriguing object.
Physical Characteristics and Location
- Distance: Located approximately 60,000 light-years from the Sun, NGC 4147 is considered a member of the Galactic halo. It’s situated at a high galactic latitude, which means it appears far from the plane of the Milky Way as seen from Earth.
- Mass and Age: The cluster has a relatively low mass of about 37,200 solar masses and an estimated age of 11 billion years, which is typical for globular clusters.
- Concentration: NGC 4147 is classified as a Class IX globular cluster on the Shapley–Sawyer Concentration Scale, indicating it has a low stellar concentration and is not very condensed towards its center.
Stellar Population and Dynamics
While many globular clusters are thought to have a single, uniform stellar population, NGC 4147 shows signs of being more complex.
- Multiple Populations: Despite its low mass, spectroscopic studies have found that NGC 4147 contains evidence of multiple stellar populations, with some stars being more enriched in light elements (like nitrogen and sodium) than others.
- Tidal Tails: The cluster exhibits faint, s-shaped tidal tails stretching outwards, suggesting that it is being tidally disrupted by the Milky Way’s gravity as it orbits the galactic center. This also indicates that the cluster follows a highly elliptical orbit.
- Association with Sagittarius Dwarf Galaxy: The orbit and location of NGC 4147 have led to speculation that it may have been captured by the Milky Way from the Sagittarius Dwarf Spheroidal Galaxy. However, recent studies suggest that its orbital dynamics are not fully compatible with this association, and it may be a genuine Milky Way globular cluster that formed in the Galactic halo.