Black Holes got their name because, well they are black. They are black because they are thought to be so massive that nothing can escape their gravitational pull, not even light.
Astronomers have for the first time observed a burst of light coming from a black hole as it was consuming matter from nearby stars.
The source of this light is approximately 7,800 light-years from Earth in the Cygnus constellation. These intense flashes lasted up to an hour and could have been observed with a simple 20-cm telescope.
“We find that activity in the vicinity of a black hole can be observed in optical light at low luminosity for the first time,” astronomer and lead researcher, Mariko Kimura from Kyoto University in Japan, told Charles Q. Choi at Space.com.
“These findings suggest that we can study physical phenomena that occur in the vicinity of the black hole using moderate optical telescopes without high-spec X-ray or gamma-ray telescopes.”
The question remains as to how this light escaped the incredible graviational pull of the black hole. The theory is that as a black hole swallows a star an accretion disk is formed. Accretion disks can create streams of plasma called relativistic jets accross an entire galaxy, hitting temperatures of 18 million degrees Fahrenheit!
The heat of this plasma gives off a bright glow which is what was observed from V404 Cygni the black hole from the Cygnus constellation. First detected by NASA’s Swift space telescope it was then tracked by Japanese researchers who alerted 26 other locations and asked them to point to V404 Cygni.
Publishing in Nature today, the team hypothesized that the light originated from X-rays produced in the centre of the accretion disk, and these X-rays irradiate and heat up the outer region of the disk, which causes it to emit the light that we can observe.
“We’re very pleased that our international observation network was able to come together to document this rare event,” said co-author, Daisuku Nogami.
More research is needed to confirm the hypothesis but it certainly indicates that we still have a lot to learn about black holes.