Nature:
When stars several times more massive than our Sun die, they
explode into supernovae, radiating enough energy to outshine a
galaxy. The radiation is sometimes produced by radioactive
decay, and sometimes by the explosive release of heat, or from
a collision between debris ejected by the star and material
surrounding it. Six such explosions can't be explained by any
known process, writes Jon Cartwright for
Nature. Robert Quimby of Caltech and colleagues think
that these explosions should be classified as
a new type of
supernova. All six explosions are about 10 times more
luminous than type Ia supernovae (the most commonly recorded
type), and unlike most supernovae, their main emission is UV
radiation rather than visible light. Quimby's team has
theorized that the exploding stars may have been so large that
they became unstable and threw off bits of material before
finally going nova. That material would then interact with the
final explosion, causing the intense brightness. On the other
hand, the supernovae might, in their early stages, have become
magnetars—spinning, highly magnetized neutron stars. The
very strong magnetic field of such stars would slow down their
spin, and the excess energy of their motion may have been
released to make them unusually bright.
