... English (Australia) . ... Survey Telescopes . ... Very Old Stars . ... The international team found that the amount of sodium in the stars was a very strong predictor of how they ended their lives. ... The results were a surprise тАФ all of the AGB stars in the study were first generation stars with low levels of sodium and none of the higher-sodium second generation stars had become AGB stars at all. ... тАЬIt seems stars need to have a low-sodium тАЬdietтАЭ to reach the AGB phase in their old age....