Credit: Aldo Zanetti
Astronomical and Imaging Data
| RA: | 18h 10m 44.20s |
| DEC: | -07° 12′ 27.4″ |
| Mag: | 10.34 |
| Diameter: | 7.1′ |
| Const: | Ser |
| OTA | RC 12″ |
| Focal Length | 2432 |
| Camera | PlayerOne Poseidon M |
| Site | Central Italy |
| Sky Quality | Bortle 4 |
Useful Informations
Palomar 7 (also known as IC 1276) is a globular cluster located in the constellation Serpens. It is one of the “Palomar” clusters, a group of faint globular clusters discovered in the 1950s that were difficult to detect due to their low stellar concentration or location within the galactic plane. This particular cluster is an example of the latter, as its light is heavily obscured by interstellar dust and gas.
Physical and Scientific Properties
- Apparent Magnitude: Palomar 7 has an apparent visual magnitude of approximately 10.3, making it too faint to be seen with the naked eye. It requires at least a small telescope for observation, and even then, it can appear as a faint, diffuse patch of light.
- Diameter: The cluster’s apparent angular diameter is about 7.1 arcminutes, which, at its distance, corresponds to a physical diameter of roughly 41 light-years. It has a low concentration of stars, which is classified as a Shapley-Sawyer concentration class XII, one of the least dense on the scale.
- Galactic Position: Palomar 7 is located approximately 17,600 light-years from Earth. Its position within the central region of the Milky Way, close to the Galactic disk and in the direction of the Galactic bulge, means its light is significantly affected by interstellar extinction, which makes it appear redder and fainter than it actually is.
- Age and Metallicity: The cluster is considered an ancient object, with an estimated age similar to other globular clusters. It is classified as a metal-rich globular cluster for its type, with a metallicity ([Fe/H]) that is higher than the typical metal-poor halo clusters. This suggests it formed from gas that had already been enriched by previous generations of stars, a characteristic shared by other clusters in the galactic bulge.