Research NewsAstronomy

Could Stellar Ash Revise Cosmic Ages?

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Science  13 Dec 1996:
Vol. 274, Issue 5294, pp. 1837
DOI: 10.1126/science.274.5294.1837a


The helium and other elements made by nuclear burning in red giant stars were thought to stay bottled up deep inside the stars, but observers have noticed that some of this ash leaks to the stellar surface. A new set of calculations now shows that the ash makes the giants brighter than expected, which in turn casts doubt on a whole set of assumptions that had pegged the age of the oldest stars at 15 billion years—substantially older thanother benchmarks of cosmic age.