On #BlackHoleFriday, a black hole is devouring a distant star

27 Nov 2015

An artist's drawing of a black hole named Cygnus X-1 pulling in matter from a adjacent blue star. Image via NASA/CXC/M.Weiss

It’s not everyday astronomers get to see a giant black hole tear a star to shreds, in fact, it’s the first time scientists have ever seen it and it’s certainly getting them excited.

In fact, the black hole is so powerful that as it comes into contact with the star approximately the same size as our sun, it is ejecting an enormous flare at speeds nearly equalling the speed of light.

While certainly nothing to fear, this cosmic fireworks display is one of the closest examples of such an event being observed by astronomers at a distance of 300m light years away, compared with previous examples being at least three times further away.

Publishing its findings in the journal Science, the team from John Hopkins University (JHU) were following up on an investigation into the star that began back in December 2014 with a team from Ohio State University.

The leader of the JHU team, Sjoert van Velzen, had decided to act quickly following the previous team’s discovery by aiming a radio telescope in its direction and, just in time, managed to catch the black hole and flare in action.

This find, not only being something special to observe, was important in proving a theory held in astrophysics that suggested that when a black hole was consuming a huge amount of gas, such as a star, it would then force its way out near the black hole’s rim, otherwise known as its event horizon.

“These events are extremely rare,” van Velzen said. “It’s the first time we see everything from the stellar destruction followed by the launch of a conical outflow, also called a jet, and we watched it unfold over several months.”

It was important to observe the event over a long period of time, the team said, due to the need to rule out the possibility that the light was from a pre-existing expansive swirling mass, otherwise known as an ‘accretion disk’, which forms when a black hole is sucking in matter from space.

The find is particularly special for van Velzen who, having only completed his doctoral dissertation last year, had said then that he hoped to discover this phenomenon within the next four years, which he has now achieved with some time to spare.

Today’s news also happens to coincide with what NASA is calling #BlackHoleFriday, a day in which it aims to promote the science and understanding behind what remains one of the most mysterious phenomena in the universe.

Colm Gorey was a senior journalist with Silicon Republic