Revista mexicana de astronomía y astrofísica
versión impresa ISSN 0185-1101
GUERRERO, C. A.; PENA, J. H. y SAREYAN, J. P. uvby-β Photoelectric Photometry of the Open Clusters NGC 1647 and NGC 1778. Rev. mex. astron. astrofis [online]. 2011, vol.47, n.1, pp. 185-192. ISSN 0185-1101.
We present photometry uvby - β for 35 stars in the direction of the open cluster NGC 1647 and for 16 stars in the direction of the cluster NGC 1778. From the analysis of the data obtained for NGC 1647 we determine a mean reddening of E(b -y) = 0.32 ± 0.02 mag and a distance modulus of V0 - MV = 8.75 ± 0.09 corresponding to a distance d = 564 ±106 pc; also, we find the cluster member stars and a numerical value of log age (in years) = 7.89 ±0.23. From the analysis of data obtained for NGC 1778, we conclude that it is not possible to determine whether there is a cluster in that direction, because the distances found for the observed stars are very different.
Palabras llave : open clusters and associations [individual (NGC 1647, NGC 1778)]; techniques [photometric].