The RR Lyrae fundamental red edge

Abstract

view Abstract Citations (11) References (24) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS The RR Lyrae Fundamental Red Edge Bono, G. ; Caputo, F. ; Castellani, V. ; Marconi, M. ; Staiano, L. ; Stellingwerf, R. F. Abstract The dependence of the pulsation red edge on mass and helium abundance was investigated on the basis of sequence of nonlinear, nonlocal, and time-dependent convective models of RR Lyrae stars. The radial pulsating envelope models were computed for two different luminosity levels and for a wide range of effective temperature. At variance with previous investigations, it was found that a fixed mass and luminosity level an increase in the helium abundnace moves the location of the red edge of the instability strip slightly toward higher effective temperatures. The discrepancy between the present investigation and previous ones is connected with the increased spatial resolution of the models which causes a substantial increase in the pulsation driving in the hydrogen ionization region. As a consequence, the red edge shows a weaker dependence on helium than on hydrogen abundance. Moreover, the sequences of models computed at fixed luminosity level and chemical composition show quite clearly that an increase in the stellar mass causes a shift of the red edge toward effective temperatures. Finally, the comparison between theoretical red edges and transition line of two metal-poor globular clusters (M15, M68) is also discussed. Publication: The Astrophysical Journal Pub Date: March 1995 DOI: 10.1086/175430 Bibcode: 1995ApJ...442..159B Keywords: Abundance; Helium; Horizontal Branch Stars; Stellar Convection; Stellar Luminosity; Stellar Mass; Stellar Oscillations; Variable Stars; Color-Magnitude Diagram; Hydrogen Ions; Metallicity; Stellar Models; Temperature; Astrophysics; GALAXY: GLOBULAR CLUSTERS: INDIVIDUAL MESSIER NUMBER: M15; GALAXY: GLOBULAR CLUSTERS: INDIVIDUAL MESSIER NUMBER: M68; STARS: ABUNDANCES; STARS: EVOLUTION; STARS: HORIZONTAL-BRANCH; STARS: OSCILLATIONS; STARS: VARIABLES: OTHER RR LYRAE full text sources ADS | data products SIMBAD (2)