Supernova may offer new view of early universe
The star's 'monster' explosion, observed last September, is the biggest ever seen.
from the May 8, 2007 edition
Page 3 of 3
How a star obliterates itself
But theorists suggest that some of the early stars – from 140 to 260 times the sun's mass – are so hot in the center that the gamma rays they emit spontaneously change into electrons and their antimatter counterparts, positrons.
As a result of this conversion, the star starts to collapse. It experiences runaway thermonuclear reactions that form heavier elements but also lead to an explosion that leaves nothing behind but shards of elements heavier than hydrogen and helium. Such blasts would achieve energies some 100 times higher than typical supernovae. And radiation from decaying radioactive nickel, created in vast quantities in the blast, would keep the supernova's lamp lit far longer than usual.
This mechanism is controversial, Filippenko says. Given the far different conditions in the local, older universe – which would embrace Supernova 2006GY – the supernova should not have gone off at all. Invoking the early-universe explanation came "out of desperation," he says, because no other explanation fit the data.
Still "it's the best candidate to date," says Dr. Livio.
RSS feed
