Chandrasekhar Limit exceeded?

From:
http://edition.cnn.com/2006/TECH/spa...eut/index.html

quote
Scientists have believed that dying stars known as "white dwarfs" can't
expand to more than 1.4 times the size of our sun without exploding in a
massive thermonuclear blast.
That rule, known as the "Chandrasekhar Limit," has served as the foundation
of decades of astrophysical research and helped scientists estimate the size
of the universe.
But a team of astronomers said on Wednesday that they have found a supernova
in a galaxy 4 billion light years away that reached a mass twice that of the
sun before exploding.
"It should not be possible to break this limit but nature has found a way,"
said Andy Howell, the University of Toronto researcher who discovered the
supernova.
"Now we have to figure out how nature did it," Howell said in a statement.
end quote

It ultimately did explode, so I'm not sure how one could argue that the
Chandrasekhar limit was violated.

The Chandrasekhar limit could in theory be exceeded if the dwarf were to
contain some hydrogen nuclei. Hydrogen has only half as much mass per
electron as the elements whose nuclei are usually found in dwarfs, and
with this more favorable ratio the dwarf can remain stable to higher
mass. It is not plausible to suppose that the dwarf was entirely made
of hydrogen, but one could have a dwarf that either contained some
residual hydrogen nulei or later accreted them.

--OL