We’ve all seen the tremendous mess babies and toddlers make when they’re eating.
Well, imagine that on a cosmic scale and scientists say you’ll have some indication as to what it looks like when certain types of black holes devour wayward stars.
In essence, it involves taking a few bites and then flinging the remains across the universe.
Researchers at Northwestern University in Illinois made their discovery after creating 3D computer simulations of what would happen if stars the size of our sun were tossed within reach of so-called intermediate-mass black holes.
The results weren’t pretty.
Analysis: Northwestern University researchers created 3D computer simulations of what would happen if stars the size of our sun were tossed within reach of so-called intermediate-mass black holes. This simulation image shows a wayward star circling a black hole
Much like prey getting caught in a spider’s web, the amuse-bouche to what becomes a lengthy and violent meal is the star first getting drawn into a black hole’s orbit.
THE THREE TYPES OF BLACK HOLE
Stellar: About three to 10 solar masses
Intermediate-mass: 100 to 100,000 solar masses
Supermassive: Millions to billions of solar masses
Then, every time the stellar visitor makes a single lap of its new neighbour the black hole takes a bite.
Further cannibalising ensues with each subsequent circle until nothing is left but the star’s misshapen and incredibly dense core, the researchers said.
Done with its meal, the black hole would then theoretically eject the scant remains across the galaxy it sits in.
Not only do these new simulations offer fresh insights into the behaviours of intermediate-mass black holes, they could also provide astronomers with the clues needed to finally pinpoint where exactly these hidden giants sit in the universe.
While astrophysicists have proven the existence of lower and higher-mass black holes, intermediate-mass ones have remained elusive and theoretical.
‘We obviously cannot observe black holes directly because they don’t emit light,’ said Northwestern’s Fulya Kıroğlu, who led the study.
‘So, instead, we have to look at the interactions between black holes and their environments.
‘We found that stars undergo multiple passages before being ejected. After each passage, they lose more mass, causing a flair of light as its ripped apart.
‘Each flare is brighter than the last, creating a signature that might help astronomers find them.’
Look out! Much like prey getting caught in a spider’s web, the amuse-bouche to what becomes a lengthy and violent meal is the star first getting drawn into a black hole’s orbit (depicted)
The three types of black hole are stellar ones, those that are intermediate-mass and supermassive variations.
The former are about three to 10 times the mass of our sun and are created when supernovae collapse.
On the other end of the spectrum, supermassive black holes are millions to billions times the mass of our sun and lurk at the heart of galaxies.
If they do exist as thought, intermediate-mass black holes would be somewhere in the middle — 10 to 10,000 times more massive than stellar remnant black holes but not nearly as big as supermassive black holes.
However, experts are yet to find indisputable observational evidence to show that they do.
‘Their presence is still debated,’ Kıroğlu said. ‘Astrophysicists have uncovered evidence that they exist, but that evidence can often be explained by other mechanisms.
Mysterious: The three types of black hole are stellar ones, those that are intermediate-mass and supermassive variations (stock image)
‘For example, what appears to be an intermediate-mass black hole might actually be the accumulation of stellar-mass black holes.’
To explore how these mysterious objects might behave, Kıroğlu and her team developed a series of new simulations.
This enabled them to discover that stars could orbit an intermediate-mass black hole as many as five times before finally being ejected.
The process, the researchers claim, would create a stunning light show that should help astronomers recognise – and prove the existence of – intermediate-mass black holes.
‘It’s amazing that the star isn’t fully ripped apart,’ Kıroğlu said.
‘Some stars might get lucky and survive the event. The ejection speed is so high that these stars could be identified as hyper-velocity stars, which have been observed at the centres of galaxies.’
Kıroğlu next plans to simulate what would happen if various types of stars – including binary and giant stellar masses – come into contact with black holes.
The new study has been accepted for publication in The Astrophysical Journal.
BLACK HOLES HAVE A GRAVITATIONAL PULL SO STRONG NOT EVEN LIGHT CAN ESCAPE
Black holes are so dense and their gravitational pull is so strong that no form of radiation can escape them – not even light.
They act as intense sources of gravity which hoover up dust and gas around them. Their intense gravitational pull is thought to be what stars in galaxies orbit around.
How they are formed is still poorly understood. Astronomers believe they may form when a large cloud of gas up to 100,000 times bigger than the sun, collapses into a black hole.
Many of these black hole seeds then merge to form much larger supermassive black holes, which are found at the centre of every known massive galaxy.
Alternatively, a supermassive black hole seed could come from a giant star, about 100 times the sun’s mass, that ultimately forms into a black hole after it runs out of fuel and collapses.
When these giant stars die, they also go ‘supernova’, a huge explosion that expels the matter from the outer layers of the star into deep space.
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