We have presented the first results of a survey of nearby galaxies for detecting and studying Cepheids, and we have proven the utility of the white-light-band Wh observations, i.e. no filter, for reaching this goal. About 43 population I Cepheids with estimated luminosity as faint as have been detected in field A of IC 1613, while only 9 of them were previously known; most of the new stars have short period or small amplitude. A detailed study of these and of population II Cepheids will be reported in Paper II.
The main conclusion of the present paper is the proposal of a new strategy for studying Cepheids as distance indicators. Relatively small telescopes and the Wh-band can be used for the survey of nearby galaxies looking accurately for Cepheids. Then just one V, R and/or I images taken with a two or three times larger telescope are needed in order to obtain the photometric data useful for the construction of the PL relation for those galaxies. Of course, the procedure can be extended to far galaxies observed with comparatively larger telescopes. We are performing simulations for testing the advantage of this method over the standard technique when applied to VLT and HST.
© European Southern Observatory (ESO) 1999
Online publication: August 25, 1999