Cepheid variables in the Large Magellanic Cloud cluster NGC 1866. I. New BVRI CCD photometry

We report BV(RI)(C) CCD photometric data for a group of seven Cepheid varia bles in the young, rich cluster NGC 1866 in the Large Magellanic Cloud. The photometry was obtained as part of a program to determine accurate distanc es to these Cepheids by means of the infrared surface brightness technique and to improve the LMC Cepheid database for constructing Cepheid P-L and P- L-C relations. Using the new data together with data from the literature, w e have determined improved periods for all variables. For five fundamental mode pulsators, the light curves are now of excellent quality and will lead to accurate distance and radius determinations once complete infrared ligh t curves and radial velocity curves for these variables become available.