Scientific Rationale

Workshop format


The existence of blue straggler stars, which appear younger, hotter, and more massive than their siblings, is at odds with a simple picture of stellar evolution, as such stars should have exhausted their nuclear fuel and evolved long ago to become cooling white dwarfs. Observations have revealed that blue stragglers exist in globular clusters, open clusters, dwarf spheroidal galaxies of the Local Group (dSph), and OB associations. Field blue stragglers have also been identified from their anomalous kinematics and metallicity. An accumulation of observational evidences now points to the fact that the two mechanisms thought to be responsible for blue stragglers – merger and mass transfer – are operating in the same cluster: the exact preponderance of one mechanism over the other possibly depending on the cluster’s property, that is, the blue straggler’s ecology. For example, it would seem natural that the most populous systems, i.e. globular clusters, should produce the largest population of blue stragglers, irrespective of the mechanism involved. Recently, however, it was shown that galactic open clusters seem to contain the largest proportions of blue stragglers, only approached by the low-luminosity dSphs.

The workshop will cover all the relevant aspects of blue straggler stars research and will be introduced by comprehensive invited review talks: Observations of blue stragglers in their various environments will be presented by A. Geller, F. Ferraro, Y. Momany, and George Preston; Binary stars and formation channels will be reviewed by H. Boffin, N. Ivanova, M. Davies and H. Perets. S. McMillan will provide a review on the dynamics of globular clusters, while the interpretation of observational data and comparison with models will be covered by L. Deng, C. Knigge, and A. Sills. The conference summary will be given by R. Mathieu.

The workshop, limited to 100 participants, will take place at the ESO premises in Santiago, Chile.

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The workshop is sponsored by ESO.