New VLT observations create major headache for stellar
theories
Astronomers expect that stars like the Sun will blow off
much of their atmospheres into space near the ends of their lives. But new
observations of a huge star cluster made using ESO’s Very Large Telescope have
shown — against all expectations — that a majority of the stars studied simply
did not get to this stage in their lives at all. The international team found
that the amount of sodium in the stars was a very strong predictor of how they
ended their lives.
The way in which stars evolve and end their lives was for
many years considered to be well understood. Detailed computer models predicted
that stars of a similar mass to the Sun would have a period towards the ends of
their lives — called the asymptotic giant branch, or AGB [1] — when they
undergo a final burst of nuclear burning and puff off a lot of their mass in
the form of gas and dust.