Strömgren uvby photometry of the open clusters NGC 6192 and NGC 6451

We have investigated the two open clusters NGC 6192 and NGC 6451 for which widely different reddening values and thus ages and distances via Strömgren uvby photometry can be found in the literature. Our measurements allow us to disentangle the apparent discrepancies in the literature and to derive new accurate values. From appropriate calibrations we find that the overall abundance for NGC 6192 is about solar whereas a subsolar value for NGC 6451 was estimated. From two previous reported photometrically candidate CP stars, one within NGC 6192 shows Strömgren indices typical for a B8 Si star whereas the one in NGC 6451 is most probably a foreground G-type star.

Based on observations at the Cerro Tololo Inter-American Observatory which is operated by the Association of Universities for Research in Astronomy Inc. (AURA), under a cooperative agreement with the National Science Foundation as part of the National Optical Astronomy Observatories.