Title: Evolution versus pulsation along the horizontal branch of M15
Abstract: view Abstract Citations (6) References (20) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Evolution versus Pulsation along the Horizontal Branch of M15 Simon, Norman R. Abstract The study combines the horizontal-branch tracks (HBETs) of Lee and Demarque (1990) with the period/mean density law of pulsation theory in order to account for the observed periods and relative luminosities of 62 RR Lyrae stars in the extreme metal-poor globular cluster M15. These tests were performed for a number of assumed values for the mean luminosity of the M15 RR Lyrae sample and for different assumed boundaries for the pulsational instability strip. It was found that no single set of models could account for all the RR Lyrae periods and luminosities while simultaneously reproducing the observed value for the the ratio of blue to variable stars. The hypothesis that an RR Lyrae sample evolved near helium exhaustion along the HBETs cannot explain the relatively large number of variable stars in M15 is confirmed. Publication: The Astrophysical Journal Pub Date: March 1992 DOI: 10.1086/171068 Bibcode: 1992ApJ...387..162S Keywords: Globular Clusters; Stellar Evolution; Stellar Luminosity; Stellar Oscillations; Computational Astrophysics; Stellar Color; Variable Stars; Astrophysics full text sources ADS | data products SIMBAD (1)