Helium Core Flash and TIP of The Red Giant Branch Distances

Abstract

The luminosity at which the helium core flash is triggered in low-mass stars is well understood to be largely independent of the mass and/or the chemical composition of the layers surrounding the degenerate He core. The bolometric luminosity at core flash is then expected to be a standard candle of relatively high stellar luminosity and having low dispersion. Empirical evidence suggest that, for a wide range of atmospheric metallicities, the emergent I-band flux shares the low dispersion in luminosity predicted by theory. The early history of using the brightest stars in globular clusters as distance indicators is reviewed and contrasted with the modern, tip of the red giant branch (TRGB) method currently being employed extensively in the determination of extragalactic distances. Recent applications of the TRGB method are also reviewed. Finally, comparisons are made with the Cepheid distance scale, and prospects for future applications are outlined.KeywordsGlobular ClusterDwarf GalaxyLuminosity FunctionVirgo ClusterBolometric LuminosityThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.