When a really massive star — that is, one at least ten times more massive than our sun — reaches the end of its life and runs out of hydrogen to fuse inside its core, it certainly doesn’t go quietly into the night. Instead it explodes as a supernova (specifically a Type II supernova), violently casting off its outer layers and scattering star-forged elements throughout space, briefly outshining all other stars in its galaxy.
The steadily-expanding shells of gas and star-stuff created in the explosion remain visible long after the supernova occurs. These supernova remnants glow brightly in many wavelengths of light — some visible to our eyes, most not — each relating to specific temperatures and elements found in the cast-off debris.
As it plows through space at supersonic speeds the shockwave from the supernova remnant also interacts with interstellar material, clearing it away, compressing it, and causing it to glow as well.
Using data from NASA’s Chandra X-ray Observatory and ESA’s XMM-Netwon, astronomers have identified one such remnant in our galaxy that has swept up a surprisingly large amount of material. Named G352.7-0.1, this supernova remnant is located 24,000 light-years away in the constellation Scorpius. It has pushed aside the equivalent of 45 solar masses — that’s 45 suns’ worth of interstellar “stuff,” not including the mass of the original star.
It’s estimated that the G352 supernova occurred about 2,200 years ago, and supernova remnants of that age typically shine brightest from to the material they are blasting aside. But G352 still predominantly glows from its original cast-off debris (“ejecta”) which has remained extremely hot — like 30 million degrees Celsius hot — and shines brightly in x-rays (seen above in blue).
These observations suggest a “unique evolutionary scenario” for G352 wherein a very massive star’s eruption interacted with a surrounding dense molecular cloud, a hypothesis supported by the shell-like shapes of the infrared and radio emissions (seen in orange and purple).
The various shapes of G352′s shells earns it the title of a “Mixed-Morphology Galactic Supernova Remnant,” or MMSNR, further proof that stars don’t all die the same death.
Also curious is the lack of a leftover neutron star at the core of the supernova remnant, at least based on the latest search of the Chandra data by the team. This could mean that any remaining stellar corpse is just too small to detect — or perhaps a black hole was formed instead.
A paper describing these findings is available online here.
Source: Chandra X-ray Observatory