This Supernova Had A ‘Delayed Detonation’

In 2008, astronomers discovered a star relatively nearby Earth went kablooie some 28,000 light-years away from us. Sharp-eyed astronomers, as they will do, trained their telescopes on it to snap pictures and take observations. Now, fresh observations from the orbiting Chandra X-ray Observatory suggest that supernova was actually a double-barrelled explosion.

This composite picture of G1.9+0.3, coupled with models by astronomers, suggest that this star had a “delayed detonation,” NASA stated.

“First, nuclear reactions occur in a slowly expanding wavefront, producing iron and similar elements. The energy from these reactions causes the star to expand, changing its density and allowing a much faster-moving detonation front of nuclear reactions to occur.”

To explain a bit better what’s going on with this star, there are two main types of supernovas:

– Type Ia: When a white dwarf merges with another white dwarf, or picks up matter from a close star companion. When enough mass accretes on the white dwarf, it reaches a critical density where carbon and oxygen fuse, then explodes.

– Type II: When a massive star reaches the end of its life, runs out of nuclear fuel and sees its iron core collapse.

NASA said this was a Type Ia supernova that “ejected stellar debris at high velocities, creating the supernova remnant that is seen today by Chandra and other telescopes.”

You can actually see the different energies from the explosion in this picture, with red low-energy X-rays, green intermediate energies and blue high-energies.

“The Chandra data show that most of the X-ray emission is “synchrotron radiation,” produced by extremely energetic electrons accelerated in the rapidly expanding blast wave of the supernova. This emission gives information about the origin of cosmic rays — energetic particles that constantly strike the Earth’s atmosphere — but not much information about Type Ia supernovas,” NASA stated.

Also, unusually, this is an assymetrical explosion. There could have been variations in how it expanded, but astronomers are looking to map this out with future observations with Chandra and the National Science Foundation’s Karl G. Jansky Very Large Array.

Check out more information about this supernova in the scientific paper led by North Carolina State University.

Source: NASA