The main goal of the Sloan Digital Sky Survey (SDSS) is to produce a 3-d map of the Universe from the redshifts of one million distant galaxies. However, as a side effect of preparing this map, there will be many cases in which there are two or more duplicate observations of the same region of the sky. Such duplication is the result of the built-in overlap in each scanned great circle (or "stripe") on the sky, the overlap between adjacent sections of the same stripe, and, in the case of the so-called "Southern Survey", of the same stripe purposefully observed multiple times. In addition to these multiple photometric observations, we can synthesize photometric magnitudes from each object for which we have obtained a spectrum, allowing another chance to compare object colors at different times.
At this point (May, 2002) of the survey, we already have approximately 2.5 million multiply-observed objects classified as stars in the magnitude range of 14-21. Our analysis shows that tens of thousands of these objects show significant magnitude changes, at least some of which are likely to be new pulsators.

 
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