Vast black hole at heart of galaxy revealed by new telescopes

Astronomers have found firm evidence that there is a "supermassive" black hole lurking at the heart of the Milky Way.

Astronomers have found firm evidence that there is a "supermassive" black hole lurking at the heart of the Milky Way.

The black hole, called Sagittarius A*, or SgrA*, lies about 26,000 light years from Earth and has been identified with the help of new, powerful telescopes.

Based on the data from radio images, the black hole is 3.7 million times more massive than the Sun.

There is no danger that we, or the rest of the galaxy, are about to be sucked into it. Though SgrA* is vast, gravity falls off so quickly with distance that its pull on the average human is the same as the weight of just a few thousand bacteria.

The data, reported today in the science journal Nature, is derived from radio images of a star called S2, which orbits the galactic core once every 15 years, compared with the Earth and Sun, which take 230 million years to complete a galactic orbit together.

Astronomers say that new "adaptive optics" telescopes are letting them gaze 20 times more accurately at the distant, dusty centre of our galaxy.

"The power of adaptive optics may ... enable us to determine how material is funnelled into a supermassive black hole, or, in the case of the black hole in the Milky Way, why so little matter is consumed by it," said Karl Gebhardt, of the department of astronomy at the University of Texas, in Nature.

SgrA* is almost certainly not the closest black hole to the Earth, but it is by far the biggest in our galaxy. The discovery is in line with the fact that many of our neighbouring galaxies have black holes at their centres.

That, in turn, appears to be inevitable because the close packing of the stars at the centre of the galaxy tends to make them burn out and collapse together, first into "neutron" stars and then into black holes, which are objects so dense that even light cannot escape their gravitational pull.

Previously, scientists had not been able to rule out the possibility that Sgr A* was a collection of super-dense neutron stars, which are the result of large stars that have collapsed into dense, normal matter consisting only of neutrons – protons and electrons mashed together.

The new evidence was made possible by an instrument known as Naco, installed at the European Southern Observatory's 8.2-metre Yepun telescope in Chile last year. Naco allows the telescope's mirror to change shape to compensate for atmospheric distortion of starlight.

One of the astronomers, Thomas Ott, said: "When we included the latest Naco data in our analysis in May 2002, we could not believe our eyes. The star S2, which is the one currently closest to SgrA, had just performed a rapid swing-by near the radio source.

"We suddenly realised that we were actually witnessing the motion of a star in orbit around the central black hole, taking it incredibly close to that mysterious object."

Start your day with The Independent, sign up for daily news emails
ebooks
ebooksAn introduction to the ground rules of British democracy
Latest stories from i100
Have you tried new the Independent Digital Edition apps?
SPONSORED FEATURES
Independent Dating
and  

By clicking 'Search' you
are agreeing to our
Terms of Use.

iJobs Job Widget
iJobs General

Recruitment Genius: Senior Environmental Adviser - Maternity Cover

£37040 - £43600 per annum: Recruitment Genius: The UK's export credit agency a...

Recruitment Genius: CBM & Lubrication Technician

£25000 - £27500 per annum: Recruitment Genius: This company provides a compreh...

Recruitment Genius: Care Worker - Residential Emergency Service

£16800 - £19500 per annum: Recruitment Genius: Would you like to join an organ...

Recruitment Genius: Senior Landscaper

£25000 - £28000 per annum: Recruitment Genius: In the last five years this com...

Day In a Page

The long walk west: they fled war in Syria, only to get held up in Hungary – now hundreds of refugees have set off on foot for Austria

They fled war in Syria...

...only to get stuck and sidetracked in Hungary
From The Prisoner to Mad Men, elaborate title sequences are one of the keys to a great TV series

Title sequences: From The Prisoner to Mad Men

Elaborate title sequences are one of the keys to a great TV series. But why does the art form have such a chequered history?
Giorgio Armani Beauty's fabric-inspired foundations: Get back to basics this autumn

Giorgio Armani Beauty's foundations

Sumptuous fabrics meet luscious cosmetics for this elegant look
From stowaways to Operation Stack: Life in a transcontinental lorry cab

Life from the inside of a trucker's cab

From stowaways to Operation Stack, it's a challenging time to be a trucker heading to and from the Continent
Kelis interview: The songwriter and sauce-maker on cooking for Pharrell and crying over potatoes

Kelis interview

The singer and sauce-maker on cooking for Pharrell
Refugee crisis: David Cameron lowered the flag for the dead king of Saudi Arabia - will he do the same honour for little Aylan Kurdi?

Cameron lowered the flag for the dead king of Saudi Arabia...

But will he do the same honour for little Aylan Kurdi, asks Robert Fisk
Our leaders lack courage in this refugee crisis. We are shamed by our European neighbours

Our leaders lack courage in this refugee crisis. We are shamed by our European neighbours

Humanity must be at the heart of politics, says Jeremy Corbyn
Joe Biden's 'tease tour': Could the US Vice-President be testing the water for a presidential run?

Joe Biden's 'tease tour'

Could the US Vice-President be testing the water for a presidential run?
Britain's 24-hour culture: With the 'leisured society' a distant dream we're working longer and less regular hours than ever

Britain's 24-hour culture

With the 'leisured society' a distant dream we're working longer and less regular hours than ever
Diplomacy board game: Treachery is the way to win - which makes it just like the real thing

The addictive nature of Diplomacy

Bullying, betrayal, aggression – it may be just a board game, but the family that plays Diplomacy may never look at each other in the same way again
Lady Chatterley's Lover: Racy underwear for fans of DH Lawrence's equally racy tome

Fashion: Ooh, Lady Chatterley!

Take inspiration from DH Lawrence's racy tome with equally racy underwear
8 best children's clocks

Tick-tock: 8 best children's clocks

Whether you’re teaching them to tell the time or putting the finishing touches to a nursery, there’s a ticker for that
Charlie Austin: Queens Park Rangers striker says ‘If the move is not right, I’m not going’

Charlie Austin: ‘If the move is not right, I’m not going’

After hitting 18 goals in the Premier League last season, the QPR striker was the great non-deal of transfer deadline day. But he says he'd preferred another shot at promotion
Isis profits from destruction of antiquities by selling relics to dealers - and then blowing up the buildings they come from to conceal the evidence of looting

How Isis profits from destruction of antiquities

Robert Fisk on the terrorist group's manipulation of the market to increase the price of artefacts
Labour leadership: Andy Burnham urges Jeremy Corbyn voters to think again in last-minute plea

'If we lose touch we’ll end up with two decades of the Tories'

In an exclusive interview, Andy Burnham urges Jeremy Corbyn voters to think again in last-minute plea