Datatype: RGU

RGU is a photographic photometric system, developped and used at the Astronomical Observatory of the University of Basel. This system uses three filters R, G, U and forms two indices: G-R, U-G.

Generally, the published magnitudes and colors are based on a small number of plates, and the scatter in the photometric diagrams is rather large.

These data provide a rough definition of the cluster characteristics and of the non-members, but they do not allow a distance and age determination precise enough by present standard. There is however a number of clusters that have not been observed in other photometric systems.

Record structure

No:Star number
Ref:Data source
G:G magnitude
G-R :G-R colour index
U-G:U-G colour index

Database access

List of clusters

Query the references
Last Update: 17 February 1998