Astronomers recently observed an enormous, dying star take a rebirth as a black hole. Interestingly, the momentous event took place with a whimper instead of a bang.
According to NASA, scientists used the Hubble and Spitzer space telescopes as well as the Large Binocular Telescope (LBT) to study a vanquished star’s remnants -- only to see that it had disappeared out of sight. The researchers had expected the star, whose mass was 25 times more than the Sun, to explode in a very bright supernova. Instead, all they saw was a fizzle out, leading to a black hole.
""Massive fails" like this one in a nearby galaxy could explain why astronomers rarely see supernovae from the most massive stars,” researcher Christopher Kochanek said. "If a star can fall short of a supernova and still make a black hole, that would help to explain why we do not see supernovae from the most massive stars."
Kochanek also added that the common belief is that only after a star goes supernova does it form a black hole. However, as many as 30 percent of stars can quietly collapse into a black hole, without requiring a supernova.
Incidentally, the recent event took place in a spiral galaxy called NGC 6946 located 22 million light-years away. The galaxy is also known as the Fireworks Galaxy due to the frequency of supernovae taking place there. A particular star called N6946-BH1 had caught the researchers’ attention in 2009. It was seen brightening weakly but appeared to have disappeared from existence by 2015.
The research team then used the power of the three telescopes to see if the star was still present -- and had simply dimmed. After detailed observation, it was seen that the star was no longer there. The study eventually concluded that the star must have turned into a black hole, after a careful process of elimination.