MASS-LOSS AND A POSSIBLE POPULATION-II LITHIUM DIP

It is shown that the recent observation of a subplateau lithium abundance for a high surface temperature (T approximately 6300 K) Population II star relative to the Population II lithium plateau can be explained by main-sequence mass loss. This explanation is identical to our previously proposed explanation for the Population I lithium dip and predicts a similar dip for Population II. It is assumed that the main-sequence mass loss in both cases is associated with the instability strip intersecting the main sequence. This mass-loss process can also decrease globular cluster ages by approximately 1 G r.