BV(RI)(C) PHOTOMETRY OF CEPHEIDS IN THE MAGELLANIC CLOUD

We report BT/(RI)(C) data for a select group of 14 Cepheids in the Lar ge Magellanic Cloud and eight in the Small Magellanic Cloud that have preexisting radial velocity curves. The photometry was obtained as par t of a program to determine distances to these Cepheids by means of th e visual surface brightness technique and to improve significantly the optical BV(RI)(C) light curves of Magellanic Cloud Cepheids. The data were acquired on the 0.9 m telescope at Cerro Tololo Inter-American O bservatory with the CFCCD instrument and with the 1 m photometric tele scope at ESO using aperture photometry. The median number of measures per Cepheid is 46 in each band, and the uncertainty in the photometry is typically +/-0.01 mag. Using these data together with data from the literature, we determined improved periods for all variables. For mos t of the Cepheids, these revised periods lead to excellent, low-noise light curves, but for a few variables, the periods are obviously varia ble.