Red Supergiant Star Death a “Massive Fail”

Red Supergiant Star Death a
Red Supergiant Star Death a "Massive Fail"

Astronomers deemed a red supergiant star to be a “Massive Fail” when it appeared to bypass becoming a supernova and collapsed down into a black hole.


A red supergiant, twenty-five times larger than our sun, skipped the anticipated stage of becoming a supernova. Instead, it quietly slipped into the state of being a black hole. Astronomers have been observing N6946-BH1 since 2009. This was the time when the star appeared brighter in the night sky, signaling it was about to die.

However, during 2015 the star, which initially became over a million times more brighter than our sun, became undetectable. The red supergiant was positioned in what astronomers have called the Fireworks Galaxy. Additionally, the star sat 22 million light years from our solar system. Researchers in Arizona had been monitoring it with the Large Binocular Telescope when it slipped out of view. This was despite their expectations that they would imminently see a spectacular explosion.



Dust cloud or massive fail?

Astronomers have always held a consensus assumption that the death of a star results in a supernova. They assumed it always passed this stage before becoming a black hole. An additional six dying stars observed during the past seven years all became supernovae as anticipated. However, the researchers felt stumped by what happened with N6946-BH1’s mysterious disappearance.

Initially, they wondered if a giant dust cloud had formed which obscured the view of the star. Astronomers aimed a further two telescopes, the more powerful Spitzer and Hubble, in the direction of where the star was. Nevertheless, they still were unable to identify where it had gone.

Additionally, the researchers were unable to detect any infrared radiation emitting from the area. Apparently, if an enormous cloud of dust were shrouding the outcome of the star’s death throes, there would at least be a small reading of this infrared radiation. The astronomers believe that this points to evidence that the red supergiant quietly collapsed into a black hole without any associated fanfare.



New understanding of black hole births

Astronomers are now beginning to gain a new understanding of how black holes’ form. In spite of their original assumption about supernovae being a standard part of the process, they can see how in many other instances, the star bypasses the supernovae stage. In fact, when they review the evidence and data they have gathered from other observations, they note that at least 30% of stars bypass the supernova stage.

The science behind the bypass fits with their new understanding. According to the Schwarzschild radius (also known as the gravitational radius), when compressing an entire object’s mass the escape velocity is at the speed of light. In other words, this creates a black hole. The Schwarzschild radius in effect becomes known as the event horizon.

Despite astronomers experienced an anti-climax when they were unable to witness a supernova. However, they have instead accumulated a greater understanding of the vast universe we inhabit. Researchers published a paper in the Monthly Notices of the Astronomical Society about this fascinating and newly understood phenomenon this year.