Stellar models are one of the backbones of modern astronomy. ... Here we review the evolution and importance of core helium burning stars and then discuss a range of methods, both theoretical and observational, that we are using to advance the models. Known observationally as SdB, red clump, horizontal branch, and second clump stars, core helium burning stars are numerous and relatively luminous and therefore contribute disproportionately to distant/extragalactic emission. ...

... Printed in U.S.A. THE STELLAR DISK THICKNESS OF LOW SURFACE BRIGHTNESS GALAXIES D. Bizyaev 1,2,3 and S. Kajsin 4 Received 2003 October 23; accepted 2004 June 9 ABSTRACT We present surface photometry results for a sample of 11 edge-on galaxies observed with the 6 m telescope at the Special Astrophysical Observatory, Russia. ... We find from a comparison of photometric scales that the stellar disks of LSB galaxies are thinner than those of high surface brightness ( HSB) galaxies. ... UGC 11301 .. ...