Astronomers Discover First Ever Supernova Remnant Made Up of Three Bubbles Inside One Another in M33 Galaxy

A team of astronomers led by researchers from the Instituto de Astrofísica de Canarias, (IAC) has discovered the first known case of three supernova remnants one inside the other.

According to a paper published in the journal Monthly Notices of the Royal Astronomical Society, the triple-bubble was found while the researchers were observing the galaxy M33 in our Local Group of galaxies using the BUBBLY programme. BUBBLY is a method developed within the team to detect huge expanding bubbles of gas in interstellar space.

It has been previously known the superbubbles around large young star clusters have a complex structure due to the effects of powerful stellar winds and supernova explosions of individual stars. Bubbles from individual supernova explosions may end up merging into a superbubble. However, researchers noted that it is the first time that they have detected a three concentric expanding supernova shells.

The researchers were baffled by their discovery because it is widely accepted that supernova expels only around ten times the mass of the sun, which lead them to ask where the second and the third supernovas get their gas if the first supernova already expels all the gas.

Artemi Camps Fariña, the first author of the study, believes that the surrounding gas and the inhomogeneous interstellar medium might have influenced the formation of the triple-bubble.

"It must be that the interstellar medium is not at all uniform, there must be dense clumps of gas, surrounded by space with gas at a much lower density. A supernova does not just sweep up gas, it evaporates the outsides of the clumps, leaving some dense gas behind which can make the second and the third shells," explained Fariña in a statement.

Researchers believe that the presence of the triple-bubble might shed some light in the feedback phenomenon. According to the study without a widespread feedback process, spiral galaxies would have shorter lives and our very own existence would be improbable.