Joint Discussion 8: Stellar Evolution in Real Time, Part II: Explicit Evidences for Stellar Evolution

Extract

This Part of the report contains the summaries of the most affirmative conclusions about recognized evidences for stellar evolution. We would certainly prefer to know that we have actually discovered this or that piece of evidence but it can be equally valuable to know that the present state of knowledge forbids a conclusion of the sort which we wish. Not surprisingly, there are instances for which we are lucky to be able to make only a limiting statement about the matter. So affirmative here really means that a conclusion - positive or negative - has actually been attained. To the layman in stellar evolutionary studies it may be surprising that there exists such a diversity of evolutionary criteria - radiometric, spectrometric, orbital dynamical, spin dynamical - all with a defined time base available at the present day. It may be hoped that some of the conclusions summarized here will make their way routinely into undergraduate texts in the for seeable future and that tools such as the HRD or CMD will not appear as only static snapshots.