Stunning NASA video made into a 13-year timelapse reveals the slow expansion of a supernova’s debris cloud and the spreading shock waves created by the explosion.
Located 11,000 light years from the Earth, Cassiopeia A is the remnant of a supernova explosion that is believed to have occurred around the year 1680.
The cloud has been repeatedly observed over the past two decades by NASA’s Chandra telescope, which can see the X-rays produced by the energetic debris.
Last year, experts used Chandra data to show that the debris also hosts unusually powerful reverse shock waves that travel back towards the heart of the cloud.
Located around 11,000 light years away from the Earth, Cassiopeia A or ‘Cas A’, as it is often dubbed is a co-called supernova remnant.
This is the glowing debris field generated after a massive star ran out of fuel, began to collapsed in upon itself before exploding as a supernova, one of the brightest observable phenomena in the night sky.
Astronomers believe that Cas A may have gone supernova in the year 1680, although there are no verified historical accounts to support this hypothesis.
The shock waves generated by this colossal explosion supercharged the supernova remnant, causing the debris clouds to glow bright in many wavelengths of light, notably those in the X-ray part of the spectrum.
This light has been seen by NASA’s Chandra X-ray observatory, even making up the first full image taken by the space telescope which was released on August 26, 1999.
Chandra’s first shot of Cas A was pioneering in its revelation of the dense object, a neutron star that was left behind at the heart of the supernova explosion.
Since 1999, however, Chandra has returned to observe Cas A repeatedly, which each subsequent look allowing astronomers to improve their understanding of how such supernova remains evolve over time.
The newly-released video combines more than a decade of such observations, showing how the incredibly hot gas, which reaches up to 20 million degrees Fahrenheit, has been seen slowly expanding outwards from 2000 to 2013.
By combining data from Chandra with those from NASA’s Hubble Space Telescope, scientists reveal within the cloud cooler filament-like structures of gas with temperatures as relatively low as 20,000 degrees Fahrenheit.
The footage also reveals the expanding blast wave from the supernova, seen on the outer edges of the remnant which appears blue thanks to how the expanding shock waves that produce high-energy X-ray emissions.
In fact, the shock waves, which travel at around 11 million miles per hour, accelerate particles to energies that are two times higher than presently reached by the Larger Hadron Collider, the most powerful particle accelerator on the Earth.
As such supernovae blast waves encounters material in space, it slows down, generating a second shock wave, dubbed a reverse shock, that travels backwards through the debris cloud towards its heart.
These kinds of reverse shock waves are usually seen to be faint, and move much slower than the original blast wave that generated them.
However, astronomers led by Toshiki Sato of Japan’s RIKEN research institute and NASA’s Goddard Space Flight Center identified reverse shocks in Cas A’s debris that are instead bright and fast moving, reaching around 5–9 million miles per hour.
The team believe that these unusually energised reverse shocks are caused by the blast waves encountering clumps of material.
These clumps cause the blast wave to slow down more rapidly that it otherwise would, energising the reverse shock and making it brighter and faster.
The full findings of the study were published in The Astrophysical Journal.