Artist’s impression of a huge outburst shooting out of the Milky Way (Image: James Josephides/ Astro 3D)

The supermassive black hole at the centre of humanity’s home galaxy exploded ‘not that long ago’.

Scientists have discovered that the region near dark beast emitted a ‘titanic beam of energy’ which ‘sliced through the Milky Way’.

This ‘cataclysmic’ blast was so powerful that it rocketed out into the Magellanic Stream – a stream of gas lying some 200,000 light years from our galaxy.

It was ‘too huge… to have been triggered by anything other than nuclear activity associated with the black hole’.


Sagittarius A, the Milky Way’s black hole, is 4.2 million times more massive than the sun and is generally a ‘sleeping beauty’, said astronomers from Australia’s ARC Centre of Excellence for All Sky Astrophysics in 3 Dimensions.



“The flare must have been a bit like a lighthouse beam,’ said Professor Bland-Hawthorn, who also works at the University of Sydney.

‘Imagine darkness, and then someone switches on a lighthouse beacon for a brief period of time.’

An artist’s impression of a supermassive black hole (Image: Nasa)

The phenomenon is known as a Seyfert flare and created two enormous ‘ionisation cones’ which started at small beams and then expanded as they shot out of our galaxy.

Researchers used data collected by the Hubble Space Telescope to reveal that the massive explosion took place little more than three million years ago – which is ‘astonishingly recent in galactic terms’.

When the black hole went kaboom, the asteroid impact that killed the dinosaurs was 63 million years in the past and humanity’s ancient ancestors, the Australopithecines, had evolved Africa.

‘This is a dramatic event that happened a few million years ago in the Milky Way’s history,” says Professor Lisa Kewley, Director of ASTRO 3D.

‘A massive blast of energy and radiation came right out of the galactic centre and into the surrounding material.

‘This shows that the centre of the Milky Way is a much more dynamic place than we had previously thought. It is lucky we’re not residing there!’

The blast lasted for roughly 300,000 years – which is a long time for a human but nothing in cosmic terms.

‘These results dramatically change our understanding of the Milky Way,’ said Magda Guglielmo from the University of Sydney.

‘We always thought about our Galaxy as an inactive galaxy, with a not so bright centre. These new results instead open the possibility of a complete reinterpretation of its evolution and nature.

‘The flare event that occurred three million years ago was so powerful that it had consequences on the surrounding of our Galaxy. We are the witness to the awakening of the sleeping beauty.’

Sagitarrius A is the nearest supermassive hole to Earth and is usually more of a slumbering beast than a ravenous monster.

But it woke earlier this year and went into a feeding frenzy.

Scientists were astonished to report that it seemed to be ‘getting hungrier’ and was seen wolfing down vast amounts of gas, dust and anything else unfortunate enough to be nearby.

‘We have never seen anything like this in the 24 years we have studied the supermassive black hole,’ said Andrea Ghez, UCLA professor of physics and astronomy and a co-senior author of the research exposing the behemoths monumental appetite.



‘It’s usually a pretty quiet, wimpy black hole on a diet. We don’t know what is driving this big feast.’

Astronomers carried out 13,000 observations of the supermassive black hole on 133 different night since 2013.

Illustration of the supermassive black hole swallowing a star (Image: Nicolle Fuller/ National Science Foundation)

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Earlier this year, it was spotted glowing twice as brightly as usual, with the strange light emanating outside its ‘point of no return’ beyond which no matter can escape.

This change was ‘unprecedented’, Ghez said, but it’s not known whether the colossus is about to start gorging itself or if the glow was caused by a large one-off meal of gas and dust.

‘The big question is whether the black hole is entering a new phase – for example if the spigot has been turned up and the rate of gas falling down the black hole “drain” has increased for an extended period – or whether we have just seen the fireworks from a few unusual blobs of gas falling in,’ said Mark Morris, UCLA professor of physics and astronomy and the paper’s co-senior author.

Stargazers will continue to observe the monster and try to work out whether its ravenous greed will grow and grow.

‘We want to know how black holes grow and affect the evolution of galaxies and the universe,’ Ghez added.

‘We want to know why the supermassive hole gets brighter and how it gets brighter.’

Here's a timelapse of images over 2.5 hr from May from @keckobservatory of the supermassive black hole Sgr A*. The black hole is always variable, but this was the brightest we've seen in the infrared so far. It was probably even brighter before we started observing that night! pic.twitter.com/MwXioZ7twV — Tuan Do (@quantumpenguin) August 11, 2019

The black hole was spotted glowing strangely over four nights in April and May by astronomers at at the Keck Observatory.


Its brightness aways varies somewhat, but the scientists were ‘stunned by the extreme variations’.

Black holes do not shine, because not even light can escape their greedy maw.

But the gas, dust and other material surrounding them is often heated up and tugged around by gravity until it glows. This effect can be seen vividly in the first-ever image of a black hole, which was captured earlier this year.

This is the first-ever image of a black hole (Picture: Event Horizon Telescope)

There are several possible explanations for the hole’s strange behaviour.

It could have sucked gas from the surface of a star called S0-2, which zoomed past last summer and let loose a mighty belch of gas which may have just reached Sagittarius A*.

Another possibility involves a ‘bizarre object’ known as G2, which is probably a pair of binary stars (systems made of two stars orbiting each other).

This strange system made a close approach to the black hole in 2014 and it’s possible the dark destroyer sucked gas from the stars.

It may even have swallowed up a load of asteroids.

‘The first image I saw that night, the black hole was so bright I initially mistook it for the star S0-2, because I had never seen Sagittarius A* that bright,’ said UCLA research scientist Tuan Do, the study’s lead author.

‘But it quickly became clear the source had to be the black hole, which was really exciting.’

We’re glad to report that no matter how hungry Sagitarrius A* becomes, it is highly unlikely to eat Earth because it’s a whopping 25,640 light-years away.

Do said the radiation would have to be 10 billion times as bright as what the astronomers detected to affect life on Earth.