I saw this story referenced yesterday, but I didn’t have the time to post a note about it:
“Astronomers used to believe that all Type 1a supernovae were essentially the same brightness. That’s because they explode with the same amount of fuel. But now a supernova has been discovered that’s twice as bright as all the other Type 1a supernovae. This is a problem, since this kind of supernovae are used as standard candles, to determine distances across the Universe. Most recently, these supernovae have been used to calculate the mysterious force called dark energy that seems to be accelerating the expansion of the Universe.”
What they mean by standard candle is that if each of these Type 1a Supernovas were exactly the same size and made out of the same material (as is predicted by the up-to-now commonly accepted Chandrasekhar limit, which says that the largest a white dwarf star, which are made up of degenerate matter, can grow is only 1.4 solar masses or so) then you would expect that when these identical objects explode, the explosions would be about the same size too.
These observations indicate that we may have put too much trust in the Chandrasekhar limit as an absolute boundary. If that’s the case, astrophysicists are going to have revisit their understanding of degenerate matter, and this possibly throws the whole issue of dark energy into doubt. (Dark Energy is thought to be the cause of the apparently observed outward acceleration of matter at the edge of the visible Universe.)
There’s plenty of information about any of these topics on Wikipedia if you’re looking for more background.
Read the rest here: New Kind of Supernova Discovered
(Via Universe Today.)