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.
|G-R||:||G-R colour index|
|U-G||:||U-G colour index|
Query the references