Credit: Jim Fordice
Astronomical and Imaging Data
| RA: | 16h 53m 25.31s |
| DEC: | -22° 10′ 38.8″ |
| MAG: | 9.97 |
| Diameter: | 5′ |
| Const: | Oph |
| OTA | Stellarvue SVX152T |
| Focal Length | 1200mm |
| Camera | ZWO ASI1600MM Pro |
| Site | California |
| Sky Quality | Bortle 4 |
Useful Informations
The globular cluster NGC 6235 is a remote and relatively low concentration stellar system located in the constellation Ophiuchus the Serpent-Bearer.
Key Physical and Kinematic Parameters
NGC 6235 is a moderately bright cluster with a visual magnitude of approximately 9.97 and an apparent diameter of about 5 arc minutes.
- Location: The cluster is situated at a large distance from the Galactic center, making it a feature of the Milky Way’s outer halo. Its distance from the Sun is estimated to be around 11.5 kiloparsecs, while its distance from the Galactic Center is approximately 4.2 kiloparsecs.
- Metallicity: It is classified as an intermediate to metal poor cluster. Its iron abundance ratio, expressed as [Fe/H], is estimated to be about -1.28 ( or 10-1.28 times the Sun’s iron abundance). This metallicity is typical for clusters belonging to the older, outer halo population of the Galaxy.
- Radial Velocity: The cluster is receding from the Sun with a substantial radial velocity of approximately 87.3 kilometers per second. This positive velocity indicates it is moving away from us.
- Concentration: NGC 6235 is classified as a relatively low-concentration globular cluster, often assigned a concentration class of X or XI on the traditional scale, meaning its stars are not as tightly packed toward the center as in high-concentration clusters.
- Stellar Population: Like all globular clusters, it is an extremely old system. Its stellar population includes a small number of RR Lyrae variable stars, which are standard candles used for distance measurement.
Scientific Significance
NGC 6235 is primarily important for probing the structure and formation history of the Galactic halo due to its remote location. Its chemical and orbital properties place it firmly within the population of globular clusters that are believed to have formed in situ (in place) or were accreted from smaller satellite galaxies during the early history of the Milky Way. Its modest size and intermediate metallicity provide data points essential for understanding the full range of properties across the Galactic globular cluster system.