All stars synthesize heavy elements, but the largest supply has come from massive stars exploding as supernovas.
Since
all stars in a globular cluster are presumed to have formed at the same time, this gives a more youthful age for the clusters.
"In a more typical galaxy, you have this [central] disk where
all stars form and die -- they're all jumbled together.
Beckwith cautions that not
all stars with the apparent ability to form planetary systems may do so.