Researchers found what causes the eerie supernova glow that lasts for up to thousands of years.
The team found that in Tycho's supernova remnant a "reverse shock wave" moving inwards at 1000 times the speed of sound (Mach 1000) is heating the material and causing it to give of the glowing X-ray light, a Harvard-Smithsonian Center for Astrophysics news release reported.
A supernova is a dying star, which meets its demise in a spectacular explosion. The object itself glows for only a few weeks or months before fading away forever; but the material from the impact can glow for much longer.
"We wouldn't be able to study ancient supernova remnants without a reverse shock to light them up," Hiroya Yamaguchi, who conducted this research at the Harvard-Smithsonian Center for Astrophysics (CfA), said.
Tycho's supernova was first noticed by Tycho Brahe in 1572. At the time the discovery was extremely shocking because it was still popular knowledge that the universe was unchanging.
Modern astronomers believe the supernova is the remains of what was once a white dwarf. They believe the dying object flung silicon, iron, and possibly other elements into the surrounding environment at speeds of up to 11 million miles per hour.
When this material collided with nearby interstellar gas it created a sonic-boom-like shockwave. This wave is continuing to move outward and creating a "backwash" reverse shockwave that moves at Mach 1000.
"It's like the wave of brake lights that marches up a line of traffic after a fender-bender on a busy highway," CfA co-author Randall Smith, said.
The speedy shockwave heats the materials, causing them to fluoresce (similar to the process that lights up fluorescent bulbs). Instead of visible fluorescent light, the materials glow in X-ray.
"Thanks to the reverse shock, Tycho's supernova keeps on giving," Smith said.
The team's finding marks the first clear evidence that "collisionless" electron heating appears in Tycho's supernova remnant.
