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The development of the red giant branch. II - Astrophysical propertiesEvolutionary sequences developed in another paper are used here to investigate the properties of the red giant branch (RGB) phase transition. Results are found for compositions in the range Y(MS) between 0.20 and 0.30 and Z between 0.004 and 0.04. The transition mass M(HeF) increases as either Y(MS) decreases or Z increases. The stellar population transition age t(HeF) is virtually independent of composition and close to 0.6 Gyr. The RGB phase transition occurs almost abruptly over a mass range of only a few tenths of a solar mass or, equivalently, over a time interval of about 0.2 Gyr in the life of a stellar population. During the RGB phase transition the core mass Mc at helium ignition increases very rapidly by about 0.15 solar mass, while the luminosity at the tip of the RGB increases by about one order of magnitude. Absolute minima are found for the values of Mc and the RGB tip luminosity.
Document ID
19910031894
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Sweigart, Allen V. (NASA Goddard Space Flight Center Greenbelt, MD, United States)
Greggio, Laura (NASA Goddard Space Flight Center Greenbelt, MD, United States)
Renzini, Alvio (Bologna, Universita Italy)
Date Acquired
August 15, 2013
Publication Date
December 1, 1990
Publication Information
Publication: Astrophysical Journal, Part 1
Volume: 364
ISSN: 0004-637X
Subject Category
ASTROPHYSICS
Funding Number(s)
CONTRACT_GRANT: CNR-PSN-87,037
CONTRACT_GRANT: CNR-PSN-85,079
CONTRACT_GRANT: CNR-PSN-85,076
CONTRACT_GRANT: CNR-PSN-87,035
Distribution Limits
Public
Copyright
Other