Red giant stars ‘chemical clock’ was off

A team of astrophysicists, led by Cristina Chiappini discovered a group of red giant stars for which the ‘chemical clock’ does not work.The Leibniz Institute for Astrophysics Potsdam study found that according to their chemical signature, these stars should be old, but instead, they appear to be young when their ages are inferred using asteroseismology.

The team explained in the report the discrepancy between the tried and true chemical clock method and the newer method of astroseismology. The old ways of inferring the history of stars and planets is called “Galactic Archaeology”, which uses chemical signatures and bodily motions to determine age and activity. Using this method, the newly discovered group of red giants seemed old.
Astroseismology is a newer method to more accurately define the ages of stars using pulsation frequencies. Under this method, the red giants seemed young.
These stars were found more toward the inner galactic disc regions, an area with interesting interactions between the bar and spiral arms which may be creating a more complex situation.
“Although there were similar stars in previous surveys, they were not identified as such and only very few of them. This may explain why these stars have received little attention so far,” mused Friedrich Anders, Chiappini’s co-author.
“Future observations will provide more clues as to the origin of these stars and the complex chemical evolution of the Milky Way,” concluded Cristina Chiappini.