The ages of globular cluster stars - Effects of rotation on pre-main-sequence, main-sequence, and turnoff evolution

Abstract

view Abstract Citations (51) References (24) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS The Ages of Globular Cluster Stars: Effects on Rotation of Pre--Main-Sequence, Main-Sequence, and Turnoff Evolution Deliyannis, Constantine P. ; Demarque, Pierre ; Pinsonneault, Marc H. Abstract Evolutionary sequences for low-metallicity stars (Z ranging from 0.001 to 0.0001) to study the effects of internal stellar rotation on the evolutionary time scales in the pre-main sequence, the main sequence (MS), and around the MS turnoff. Although a substantial amount of angular momentum remains in the interior, rotation is only a minor perturbation on the structure and ages of globular cluster stars. Even models with large initial angular momenta have MS lifetimes that are within 1 percent of those of standard models of the same mass and composition. Therefore, rotation does not affect age estimates of globular clusters from isochrone fitting. Furthermore, the models suggest that because rotation is not likely to affect horizontal-branch (HB) morphology, it does not affect significantly age estimates from the Delta-V method. Nevertheless, the internal angular momentum in the models is consistent with observations of surface rotational velocities on the HB, which require the preservation of a large reservoir of internal angular momentum. Publication: The Astrophysical Journal Pub Date: December 1989 DOI: 10.1086/185611 Bibcode: 1989ApJ...347L..73D Keywords: Globular Clusters; Main Sequence Stars; Pre-Main Sequence Stars; Stellar Evolution; Stellar Rotation; Angular Momentum; Horizontal Branch Stars; Stellar Structure; Astrophysics; CLUSTERS: GLOBULAR; COSMOLOGY; STARS: EVOLUTION; STARS: POPULATION II; STARS: PRE--MAIN-SEQUENCE; STARS: ROTATION full text sources ADS | data products SIMBAD (6)