Stellar collisions and mergers in the cores of globular clusters

摘要

Rare and exotic stars are being discovered with Hubble Space Telescope (HST) observations in large numbers in the cores of globular clusters. Stellar collisions and/or mergers are likely responsible for many of these bizarre objects. I review the theoretical arguments which predict substantial populations of blue stragglers and cataclysmic binaries - the most ubiquitous of globular cluster core exotica. HST observations confirm that blue stragglers are, as predicted, very common. However, dwarf and classical novae appear to be much rarer. A possible explanation for this apparent discrepancy is that most globular cataclysmic binaries are strongly magnetic, and can effectively hide from all but the deepest HST searches. (C) 1999 Elsevier Science B.V. All rights reserved. [References: 17]