ABC Science puzzles over a star that, according to everything we know about stars, simply shouldn’t exist:
The star, called SDSS102915+172927, is reported today in the journal Nature.
It has about 80 per cent the mass of the Sun and is composed almost entirely of hydrogen and helium, something previously thought impossible.
…
“Accepted theory predicts stars with low mass and extremely low quantities of metals, shouldn’t exist because the clouds of material from which they formed could never have condensed”, says [Dr Elisabetta Caffau from the Zentrum fur Astronomie der Universitat Heidelberg].