The elements yttrium and magnesium are produced by different types of supernovae, so their abundance ratio can be used to date the formation of solar-type dwarf stars. Slumstrup et al. investigated whether the method also works for more evolved giant stars. They obtained spectra of giant stars in four open clusters, whose ages are known by other means, to calibrate the relation. They found that the giant stars follow the same trend of Y/Mg versus age as the dwarf stars—at least when the abundance of iron is moderately high. Because giant stars are much brighter than dwarfs, this technique may be used to date individual stars that are further away from Earth.
Keith T. Smith
Science 15 Sep 2017:
Vol. 357, Issue 6356, pp. 1109-1110
DOI: 10.1126/science.357.6356.1109-e
