Open AccessRed giant depletion in globular cluster cores
Author(s) -
Beer Martin E.,
Davies Melvyn B.
Publication year - 2004
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1111/j.1365-2966.2004.07380.x
Subject(s) - physics , common envelope , red giant branch , globular cluster , red giant , astrophysics , horizontal branch , asymptotic giant branch , white dwarf , blue straggler , stellar evolution , astronomy , giant star , stars , binary star , helium , atomic physics
We investigate the observed depletion of red giants in the cores of post‐core‐collapse globular clusters. In particular, the evolutionary scenario we consider is a binary consisting of two low‐mass stars which undergoes two common‐envelope phases. The first common‐envelope phase occurs when the primary is a red giant resulting in a helium white dwarf and main‐sequence star in a detached binary. The second common‐envelope phase occurs shortly after the secondary becomes a red giant. During the second common‐envelope phase, the degenerate helium cores merge resulting in a core mass greater than the helium burning limit and the formation of a horizontal branch star. We show that stellar encounters enhance this evolutionary route in post‐core‐collapse clusters. These encounters increase the population of binary secondaries which would have evolved on to the red giant branch in the recent past.