"These changes provide evidence that the explosion's blast wave
has moved beyond the ring into a region with less dense gas.
But the explosion was so big that the blast wave
also demolished a house 100 yards away.
"We initially thought of V407 Cygni as a special case because the red giant's atmosphere is essentially leaking into space, producing a gaseous environment that interacts with the explosion's blast wave
," said co-author Steven Shore, a professor of astrophysics at the University of Pisa in Italy.
"First comes a blast wave
of high pressure that spreads out at supersonic speeds and can cause devastating internal injuries.
Theory had predicted that the source would expand by about 1 milliarcsecond per day as the blast wave
Data from NASA's Chandra X-ray Observatory suggest the latter because they indicate that the blast wave
from the supernova had slammed into material left behind by such a wind.
The blast wave
was powerful enough to shatter some windows in nearby buildings.
The video further showed the driver detonating the bomb, which set off a tremendous fireball, followed by a blast wave
that rippled across the base.
These spots light up as the supernova's blast wave
smashes into material that was probably created by colliding winds from the progenitor star tens of thousands of years before it exploded (S&T: July 2004, page 15).
This expanding blast wave
produces a steady stream of X rays.
If they do contain an actual audio recording of the test blast itself (something I'm often suspicious of-I suspect many were filmed silently and have a stock blast sound effect), it's almost always shifted in time so that the explosion and the sound of the blast wave
are simultaneous," the New York Daily News quoted him as saying.
The knots are regions where the blast wave
, rushing out at 64 million kilometers per second from the supernova, has smacked into the ring, heating it to millions of kelvins.