NGC 6934

NGC 6934 (also known as Caldwell 47) is a globular cluster of stars in the northern constellation of Delphinus, about 16 kpc distant from the Sun. It was discovered by the German-born astronomer William Herschel on 24 September 1785. The cluster is following a highly eccentric orbit (with an eccentricity of 0.81) through the Milky Way along an orbital plane that is inclined by 73° to the galactic plane. It may share a common dynamic origin with NGC 5466. As of 2018, it has been poorly studied.

This appears to be a Oosterhoff type I cluster with an intermediate metallicity. It has an Shapley–Sawyer Concentration Class of VIII, with a core radius of $1.2 arcmin$ and a half-light radius of $2.95$. The estimated mass is 295,000 times the mass of the Sun. The cluster displays photometric anomalies, with a split subgiant branch on the HR diagram. Searches for variable stars have discovered 85 in the cluster field, of which 79 are of the RR Lyrae class and one is a SX Phe variable. There is some evidence for a tidal tail.