The evolutionary state and pulsation characteristics of red variables in globular clusters

Abstract

view Abstract Citations (47) References (39) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS The evolutionary state and pulsation characteristics of red variablesin globular clusters. Frogel, J. A. Abstract Infrared observations of more than 50 red variables in globular clusters are presented, and the data are examined to ascertain the location of the variables in the H-R diagram and the implications for their evolutionary state, to find evidence of mass loss, and to determine the mode of pulsation. Particular emphasis is given to seven variables which lie considerably to the blue of their cluster giant branches and which may be in an advanced evolutionary state. It is concluded that all of the long-period variables (LPVs) in the clusters have luminosities greater than that corresponding to core helium flash, so they must be asymptotic giant branch stars. With three possible exceptions, all other cluster variables have luminosities less than that corresponding to helium core flash. Red K-L colors for the LPVs are probably indicative of relatively high mass loss rates compared to non-LPV variables. Publication: The Astrophysical Journal Pub Date: September 1983 DOI: 10.1086/161274 Bibcode: 1983ApJ...272..167F Keywords: Abundance; Globular Clusters; Red Giant Stars; Stellar Evolution; Stellar Oscillations; Variable Stars; Asymptotic Giant Branch Stars; Hertzsprung-Russell Diagram; Mass To Light Ratios; Stellar Luminosity; Stellar Mass Ejection; Stellar Spectrophotometry; Stellar Temperature; Astrophysics full text sources ADS | data products SIMBAD (17)