The main-sequence color-magnitude diagram of M 92

Abstract

view Abstract Citations (55) References (32) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS The Main-Sequence Color-Magnitude Diagram of M92 Heasley, J. N. ; Christian, C. A. Abstract A new color-magnitude (C-M) diagram for main-sequence stars in the globular cluster M 92 is presented. The observations upon which this diagram is based were obtained with an RCA CCD at the 3.6 m Canada-France-Hawaii telescope. These new data refine the position of the cluster ridge lines in the lower main sequence, the subgiant branch, and the lower giant branch. A comparison of the new C-M diagram with new theoretical isochrones shows that the shapes of the models are in good agreement with the observations, but a large shift in color is required to bring the theory and observations into agreement. Possible explanations for this discrepancy are discussed. The new M 92 observations and recent work on M13, M15, and 47 Tuc combined with the new isochromes show that the globular cluster distance scale developed by Sandage from the RR Lyrae period-luminosity-amplitude relation is consistent for the relative distances if all the clusters are the same age. Publication: The Astrophysical Journal Pub Date: August 1986 DOI: 10.1086/164459 Bibcode: 1986ApJ...307..738H Keywords: Color-Magnitude Diagram; Globular Clusters; Main Sequence Stars; Stellar Evolution; Charge Coupled Devices; Chronology; Stellar Models; Stellar Spectrophotometry; Astrophysics; CLUSTERS: GLOBULAR; STARS: EVOLUTION full text sources ADS | data products SIMBAD (10)