Collaborative Project: Observations of Cepheids in Local Group Galaxies

Purdue Research Foundation, West Lafayette IN

Investigators

Abstract

ABSTRACT Moffett, Thomas "Collaborative Project: Observations of Cepheids in Local Group Galaxies" AST-9987347 This is a collaborative project to obtain radial velocity curves and abundance determinations for Cepheid variable stars in the galaxies M31 and M33. Cepheid variable stars provide the primary means for determining the extragalactic distance scale. This project will test the assumption that Cepheids outside our own Milky Way Galaxy and its satellites the Magellanic Clouds follow the same period-luminosity-abundance relation. Candidates will be gleaned from the DIRECT photometry survey of nearby galaxies. The spectroscopic observations of candidates will be performed with the Hobby-Eberly Telescope at McDonald Observatory. The results will provide one of the first direct calibrations of distances in the Local Group of galaxies, and help refine the extragalactic distance scale upon which the determination of the Hubble constant depends. Funding for this project was provided by the NSF program for Stellar Astronomy & Astrophysics (AST/SAA).