Credit: Jim Fordice
Astronomical and Imaging Data
| RA: | 17h 43m 42.20s |
| DEC: | -26° 13′ 21.0″ |
| MAG: | 11.55 |
| Diameter: | 1.2′ |
| Const: | Oph |
| OTA | Planewave CDK24 |
| Focal Length | 3962mm |
| Camera | QHY 600M |
| Site | El Sauce Observatory,Río Hurtado, Chile |
| Sky Quality | Bortle 1 |
Useful Informations
Palomar 6 is a globular cluster in the constellation Ophiuchus that is a member of the Palomar Globular Clusters group, known for their typically faint appearance. It is a classic example of an old-bulge globular cluster, meaning it formed and resides within the central bulge of the Milky Way galaxy, rather than the more common galactic halo.
Location and Visibility
Palomar 6 is situated approximately 25,000 light-years from the Sun. Its unique position close to the Galactic Center means the line-of-sight to the cluster passes through the heavily dust-obscured regions of the inner Milky Way. This results in significant interstellar reddening, where the cluster’s light is absorbed and scattered, making it appear much fainter and redder than it truly is, and complicating photometric studies. This heavy obscuration is the primary reason for its relatively late discovery in the 1950s during the Palomar Observatory Sky Survey.
Physical and Stellar Properties
Palomar 6 is classified as a relatively loose globular cluster (Shapley–Sawyer concentration class XI).
- Age and Formation: It is a very ancient cluster, with an estimated age of about 12.4 billion years, making it one of the oldest structures in the galaxy and similar in age to other globular clusters found in the bulge.
- Mass: Its estimated mass is approximately 228,000 solar masses.
- Metallicity: It has a relatively high metallicity for a globular cluster, with an iron abundance ratio of approximately -0.91 dex. This metal-rich characteristic is often observed in globular clusters that formed in the dense, early-forming environment of the galactic bulge.
- Contents: The cluster contains a population of evolved stars and is also known to host at least one radio pulsar. It was historically considered one of the few globular clusters to contain a planetary nebula, JaFu 1, but recent high-precision proper motion studies have cast strong doubt on the nebula’s membership, suggesting it is likely a foreground or background object not physically associated with Palomar 6.