In fact, there were no heavy elements present at all.
Heavy elements need very high temperature and pressure to form.
However, it contained more heavy elements than might have been expected.
The supernova is the only way heavy elements can be made.
This is the first time, however, that variable stars with so few heavy elements were found.
Without the heavy elements generated in stars, Earth and everything on it, including people, would not exist.
A number of heavy elements, unseen in the natural world, were first created with this machine.
It is twice as enriched with heavy elements than the Sun.
"Should heavy elements not have sunk to form a core?"
The two stars have less than half the abundance of heavy elements as the Sun and are approximately a billion years older.