Astronomers clock a black gap spinning at half the velocity of sunshine

  • Astronomers clock a black gap spinning at half the velocity of sunshine

Astronomers clock a black gap spinning at half the velocity of sunshine

A broad band of dust and cold gas is bisected at an angle by opposing jets of high-energy particles blasting away from the supermassive black hole in the nucleus.

Through extensive analysis, the team discovered a stable, periodic signal coming from the doomed star-it appeared to brighten and fade once every 131 seconds.

Astronomers back in 2014 were searching the night sky for something cool and found what they were looking for.

Artist impression of a star being destroyed at the event horizon of a black hole. With only a couple dozen examples it would be premature to make big-picture conclusions (especially if we're not interpreting the data correctly), but the pattern might indicate that supermassive black holes grow primarily by prolonged feeding from accretion disks, which would spin the black holes up like water from a hose hitting a basketball.

As the star was devoured, an event known as a tidal disruption flare occurred.

Researchers calculate the spinning speed of the black hole to be about 50 per cent of the speed of light.

"That's not super fast - there are other black holes with spins estimated to be near 99 percent the speed of light", Pasham says. Researchers have calculated black holes' speeds before, and they can spin faster than this one, but this one's speed is nothing to sneeze at.

A team from the Massachusetts Institute of Technology (MIT) reported that as the black holes consume more star matter, its corona contracts from 100 to 10 kilometers in just over a month. This is rare. Only about 5 percent of black holes are actively doing this. This Spin is in addition to the mass, from the effect of gravity on other celestial bodies to derive the most important property of Black holes, which, however, is not easy to determine.

"At first I didn't believe it because the signal was so strong", Pasham says. "We've seen four similar events in NICER's first year, and it's remarkable".

As the second star disappeared, the remnants that astronomers have now identified would have been dragged into the white dwarf's wake, allowing us to see it for the first time - essentially lighting it up so it could be detected by telescopes. Alone, it would not have been enough to emit any sort of detectable radiation. A relatively low rotation rate would implicate mergers as the primary factor, because these random smashups likely wouldn't keep spinning the growing black hole up in the same direction. When the iron atoms closest to the black hole are bombarded by light from the core of the corona, the X-ray wavelengths they emit get stretched because time is moving slower for them than for the observer (in this case, NICER).

To confirm the decreased lag time was due to a change in the corona and not the disk, the researchers used a signal called the iron K line created when X-rays from the corona collide with iron atoms in the disk, causing them to fluoresce. As the white dwarf came in contact with this hot stellar material, it likely dragged it along as a luminous overcoat of sorts, illuminating the white dwarf in an intense amount of X-rays each time it circled the black hole, every 131 seconds. The chances of detecting such a scenario would be exceedingly slim.

However, "if you have a high-spin black hole, supermassive black hole, that's telling us that maybe steady accretion was dominant", Pasham said during a news conference at AAS Wednesday. "But now we have evidence that what is evolving in the system is the structure of the corona itself", he added. "But at least in terms of the properties of the system, this scenario seems to work". He hopes that when the European Athena X-ray mission launches in 2031, it will find many more and really break open this line of investigation.

Spin is one of the fundamental parameters that describe a black hole, like the stats on an ID card.