Multiband photometric re-classification of ROTSE-I δ Scuti type stars

We present multi-passband CCD photometry of 20 ROTSE-I Scuti type pulsating stars and 1 RR Lyrae star to re- classify their variable types using the comparison of amplitudes between V and I passbands. For the re-classification, we used a criterion that pulsating stars have larger amplitude dierences between passbands than eclipsing binaries because brightness changes of pulsating stars are mainly due to the temperature variations. As a result, only six stars were re-confirmed as Scuti variables and thirteen stars turned out to be W UMa type eclipsing binaries. The other two stars were identified as one cataclysmic variable and one non-variable, respectively. Our results suggest that a number of ROTSE-I Scuti type stars, which do not show typical pulsating light curves of high amplitude Scuti stars, are W UMa type eclipsing binaries.