MSST observations of the pulsating sdB star PG1605+072

We present the first results from the MultiSite Spectroscopic Telescope (MSST) observations of the sdBV star PG1605+072. Pulsating sdB stars (also known as EC14026 stars) offer the chance to gain new insights into the formation and evolution of extreme Horizontal Branch stars using the tools of asteroseismology. PG1605+072 is an outstanding object in its class, with the richest frequency spectrum, the longest periods, and the largest variations. The MSST campaign took place in May/June 2002 immediately following the Whole Earth Telescope Xcov22 run, which observed PG1605+072 as an alternate target. We will first give an overview of the project and its feasibility, after which we will present the massive data set, made up of 399 hours of photometry and 151 hours of spectroscopy. The overall aims of the project are to examine light/velocity amplitude ratios and phase differences, changes in equivalent width/line index, and wavelength-dependence of photometric amplitudes, and to use these properties for mode identification.