Signs In he Sun, The
Moon and The Stars
Aug 25, 2011
Nearby supernova blooms into view
By Dan Vergano, USA TODAY
An international team reports the closest exploding star seen in
four decades, offering insight how massive stars perish.
The star, located in the "Pinwheel Galaxy", M101, some 21 million
light years away (one light year is about 5.9 trillion miles),
belongs to a widely-observed Type 1a class of supernovas, or
exploding stars.
"The best time to see this exploding star will be just after
evening twilight in the Northern hemisphere in a week or so's
time," said University of Oxford astronomer Mark Sullivan, in a
statement. "You'll need dark skies and a good pair of binoculars,
although a small telescope would be even better."
Such Type 1a stellar explosions are used as standard astronomical
yardsticks to gauge how quickly distant galaxies are moving away
from each other, observations that led to the discovery that the
universe is moving apart at an accelerating rate in 1998, now
ascribed to "dark energy" acting as an anti-gravity force across
vast distances in the universe.
"Seeing one explode so close by allows us to study these events in
unprecedented detail," Sullivan said in the statement.
Astrophysicists are currently uncertain about the exact mechanism
that triggers such standard-seeming supernovas, thought to result
from either the merger of twin stars, or the accretion of gas from
one star onto another.