X-ray pulse detected near event horizon as black hole devours star

Rodiano Bonacci
Gennaio 12, 2019

So when an unassuming star traversed near this black hole, it began to rip the star apart. The findings, published in Science, focus on a supermassive black hole located nearly 290 million light years away.

ASASSN-14li was discovered in November 2014, after it tore apart a star that strayed too close. That even created a burst of X-ray activity at the center of the galaxy and since the discovery, multiple observatories have had telescopes trained on the event to learn more about how precisely black holes consume stars.

"It is very hard, the Spin of a Black hole limit, as the Spin effects occur only very close to the hole itself, where the gravity is extremely strong and it is hard to get a clear view", explains Pasham, in a communication to the European space Agency Esa.

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

Black holes are massive beasts that annihilate anything that dares to cross them.

Theoretical models of tidal disruption flares show that when a black hole shreds a star apart, some of that star's material may stay outside the event horizon, circling, at least temporarily, in a stable orbit such as the ISCO, and giving off periodic flashes of X-rays before ultimately being fed by the black hole.

Because of the stability of the signal and its proximity to the event horizon, researchers were able to calculate the spin of the black hole-roughly 50 percent of the speed of light, which would be around 93,000 miles per second.

Black holes are mysterious cosmic destroyers, but we just got one step closer to figuring out one of the key characteristics of how they work: how fast they're spinning. It is the Black holes gobble up foreign stars except.

The black hole was given the designation MAXI J1820+070, named for the instrument that first detected it, according to Phys.org.

"NICER's observations of J1820 have taught us something new about stellar-mass black holes and about how we might use them as analogs for studying supermassive black holes and their effects on galaxy formation", said co-author Philip Uttley, an astrophysicist at the University of Amsterdam.

These datasets revealed a consistent flickering: ASASSN-14li's X-ray emissions rise and fall every 131 seconds. The signal appears to periodically brighten and fade every 131 seconds, and persists over at least 450 days. It was the first Time the researchers the Tear of a star for their spinning-were able to use calculations, Pasham. The few supermassive black holes whose rotation rates have been clocked to date are in the same extreme neighborhood, generally whipping around between 33 percent and 84 percent the speed of light. Astronomers can make pretty good guesses about those black holes' masses by studying the galaxies themselves.

"The fact that we can track this region of bright X-ray emission as it circles the black hole lets us track just how quickly material in the disk is spinning", Pasham said in the same statement. For all intents and purposes, the white dwarf would have been invisible to telescopes as it circled the relatively inactive, spinning black hole. "Estimating spins of several black holes from the beginning of time to now would be valuable in terms of estimating whether there is a relationship between the spin and the age of black holes". "We would've been extremely lucky to find such a system". 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). "Their result suggests that tidal disruption events should be regularly followed up by x-ray telescopes to maximise our knowledge of their properties".

"In the next decade, we hope to detect more of these events", Pasham says.

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