Reverse Shockwaves Behind Spectacular Glow of Tycho's Supernova Remnant

Reverse shockwaves travelling inwards at Mach 1000 has lit up the remnants of Tycho's supernova, according to a new study.

Supernovas are brilliant explosions marking the death of a giant star. Latest research has found that it is the reverse shockwaves (something like sonic booms) that light up the supernova remnants, making them visible even after hundreds of years. The study team, in other words, has discovered the power behind these long-lived brilliance.  

Tycho's supernova was first seen in 1572. At that time, the dying star was so bright that it was visible even during daylight. 

"We wouldn't be able to study ancient supernova remnants without a reverse shock to light them up," says Hiroya Yamaguchi, who conducted this research at the Harvard-Smithsonian Center for Astrophysics (CfA).

Tycho's supernova shone for about a year, before becoming invisible to the naked eye. Today, the supernova gives researchers an opportunity to study cosmic particles and their behavior.

According to astronomers, Tycho was a Type Ia supernova, which is caused by the explosion of a white dwarf star. The blast sent elements into the space with speeds reaching over 11 million miles per hour (5,000 km/s).

The remnants of supernova smashed into the nearby intergalactic gases, which created a massive shockwave. The inward shockwave raced at about 1000 Mach. What we see today is the outward shockwave that is moving at Mach 300.

"It's like the wave of brake lights that marches up a line of traffic after a fender-bender on a busy highway," explained CfA co-author Randall Smith in a news release.

The reverse shockwaves heat gases inside the supernova, which lights the remnants up. The particles glow in X-rays and not visible light.

The team analyzed the X-ray spectrum of Tycho's supernova remnant and found that electrons crossing the reverse shock wave are heating up through a mysterious phenomenon. This is the first time that researchers have found remnants heating up in a "collision-less" environment. The team plans to study this process in other younger supernovae.

Tycho's supernova is named after Danish astronomer Tycho Brahe who first observed the event in 1572.