G20 protesters marching in London

Children are also joining the heavily-policed march

Thousands of people are marching through London demanding action on poverty, climate change and jobs ahead of next week’s G20 summit.

The Put People First alliance of 150 charities and unions are marching from Embankment to Hyde Park for a rally.

Speakers will call on G20 leaders to pursue a new kind of global justice.

Police say protests over the coming week are creating an “unprecedented challenge”. Campaigners have rejected claims the march could turn violent.

Marchers gathered near Embankment spoke of “a carnival atmosphere”.

“The sun is shining – there are lots of banners and flags and everyone is in good spirits,” said Chris Jordan, an Action Aid campaigner.

A huge security operation is being launched before and during the G20, at which world leaders will discuss the global financial crisis among other issues.

Prime Minister Gordon Brown has said he is optimistic that a consensus can be reached on how to tackle the problem but other leaders are less convinced.

In an interview with Saturday’s Financial Times, German Chancellor Angela Merkel dampened expectations of a significant breakthrough.

She said one meeting would not be enough to solve the economic crisis and finish building a new structure for global markets.

Ahead of the summit, there are fears that banks and other financial institutions could be the focus for violent protests.

Organisers of Saturday’s Put People First march say police have no evidence anyone intends to take part in violence or disrupt the march, which has been organised in full co-operation with the authorities.

Commander Simon O’Brien, one of the senior command team in charge of policing security, said: “It’s fair to say that this is one of the largest, one of the most challenging and one of the most complicated operations we have delivered.

“G20 is attracting a significant amount of interest from protest groups. There is an almost unprecedented level of activity going on.

“The unprecedented nature is about the complexity and scale of the operations over a number of days.”

TUC general secretary Brendan Barber, who is due to address the rally, said there was no room for violence at the march.

“If there are other groups who want to cause trouble, I don’t want to see them anywhere near our event,” he told the Today programme.

He said he wanted to see G20 leaders agree a plan of action to deal with the financial downturn.

“Where I hope we will see a consensus emerge is in the recognition that unless they act together, then the problems are only going to get worse.

“This, unlike any other recession, is a recession right across the world.”

The Energy and Climate Change Secretary Ed Miliband, who has met some of the groups taking part, said he expected “the vast majority” to stage a peaceful protest.

He said he agreed it was important for the G20 to make commitments on helping the environment as well as the economy.

“There are some people who will say you can either tackle the economic crisis or the climate crisis.

“But the truth is that both come together with this idea of a Green New Deal, of investing in the jobs of the future, which are going to be in the green industries of the future.”

‘Better world’

Actor Tony Robinson suggested the talk of violence was distracting from protesters’ demands for greater government commitment on the environment and local communities.

Jake Corn, from Cambridge, said he was joining the march to show his support for a more sustainable future.

“We feel this is an important moment with the G20 coming here. We want to get our message across to as many people as possible,” he said.

Italian trade unionist Nicoli Nicolosi, who had travelled from Rome, said: “We are here to try and make a better world and protest against the G20.”

Saturday’s march will be followed by a series of protests on Wednesday and Thursday by a variety of coalitions and groups campaigning on a range of subjects, from poverty, inequality and jobs to war, climate change and capitalism.

In the run-up to the summit, Prime Minister Gordon Brown has been visiting a number of countries seeking support.

On Friday, during a visit to Chile, he said people should not be “cynical” about what could be achieved at next week’s summit, saying he was optimistic about the likely outcome.

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Australia MPs oppose uranium sale

Australia has 40% of the world’s known uranium resources

Australia should not sell uranium to Russia, a parliamentary committee says.

It said the $800 million deal should not go ahead until Russia assuaged doubts about the separation of its civilian and military uses of uranium.

The deal was signed by former Prime Minister John Howard and Russian leader Vladimir Putin last year.

The committee said assurances were needed on Russia’s compliance with, and long-term commitment to, the Nuclear Non-Proliferation Treaty.

Opposition members of parliament supported the uranium sales. They argued Australia would benefit from the trade, and said safeguards against any future military use of the uranium were adequate.

But the report presented to parliament on Thursday recommended that “further consideration is given to the potential ramifications for this agreement”.

The committee said any facilities taking Australian uranium should be inspected by the International Atomic Energy Agency.

Russia has insisted that it would only use Australian uranium for civilian purposes, to generate power at home, and would not export it for use elsewhere.

Some reports of the committee’s findings suggested that opposition to the deal was strengthened by Russia’s recent incursions into Georgia.

Australia’s Foreign Minister Stephen Smith warned earlier this month that if Russia failed to withdraw its troops from neighboring Georgia, Australia might withhold approval of the new agreement.

Australia has 40% of the world’s known uranium resources and exports the product to more than 30 countries under strict conditions.

‘Catastrophic’ storm hits Texas

Hurricane Ike has made landfall on the Gulf coast of Texas, where it is expected to cause “potentially catastrophic” flooding and damage.

It hit land at Galveston at 0710 GMT, with winds of up to 110 mph (175km/h).

Much of the city, which in 1900 was the scene of the country’s deadliest hurricane, was already under water after a 12ft (3.7m) storm surge.

The eye of the storm, which has since weakened to a Category One, is turning away from Houston, towards Arkansas.

Outside walls and ceilings have collapsed, the glass atrium in the lobby [of our hotel] shattered

Mandatory evacuation orders affected more than one million people, but there are fears for up to 90,000 people across Texas who officials say decided to brave out the storm.

In Galveston, an estimated 23,000 residents stayed behind.

President George W Bush, who earlier declared a federal emergency in Texas, said the federal and state authorities would conduct the recovery effort together, bringing in generators and ensuring water and ice supplies.

US Homeland Security Secretary Michael Chertoff is due to arrive in Texas on Saturday, weather conditions permitting, he added, speaking at the White House.

The US Environmental Protection Agency has waived federal clean air regulations for petrol sold in states affected by the storm, in an effort to reduce fuel disruption.

Ike has halted more than a fifth of US oil production, forcing 17 refineries in the Gulf of Mexico to shut down as a precaution.

Rain and debris

Jessica Willey, a journalist based in Galveston which lies on a small island off the coast of Texas, told it was the worst storm she had ever seen:

See the likely path of Hurricane Ike through the US

“The rain is coming sideways. Debris is flying through the air. Things are getting ripped off buildings every second, and flying through the air.

All emergency workers have been pulled off the streets until daybreak when a curfew will be lifted.

“We hope we will find the people who are left here alive and well,” said Galveston mayor Lynda Ann Thomas.

There is widespread flooding, and a hospital there is under at least 9.8ft (3 meters of water). The city has lost power and a number of houses are reported to be on fire.

Residents of low-lying homes were warned they faced “certain death” if they stayed.

Haitian appeal

At 1300 GMT, Hurricane Ike was about 20 miles (30km) south-southeast of Huntsville, Texas, with top sustained winds of nearly 90mph (145km/h).

It was due to pass through eastern Texas during the day, reaching western Arkansas on Saturday night, according to US National Hurricane Center.

US officials have warned as many as 100,000 homes in Texas could be affected by flooding.

Nearly 4.5 million people in the Houston-Galveston area are without electricity, a spokesman for power company CenterPoint Energy said.

Ferocious winds and rain have been lashing at his hotel for 10 hours.

“We are largely trapped here,” he said. “The power went out five hours ago, the lowest floor is submerged. Outside walls and ceilings have collapsed, the glass atrium in the lobby shattered.

“With the threat of rising seas, hotel guests have been ushered into the concrete stairwell, the sturdiest part of the building, and urged to climb to higher floors.”

The massive system is causing flooding along the Louisiana coast, still recovering from Hurricane Gustav earlier this month.

1900 GALVESTON HURRICANE Thought to be worst natural disaster in US history 8,000 people killed 130mph (209km/h) winds and 15ft (4.6m) waves swept homes away

Authorities are trying to avoid a repeat of 2005, when some 110 people died in Houston during a chaotic evacuation in the face of Hurricane Rita.

Mr Chertoff said Ike was a “potentially catastrophic hurricane”.

Earlier, it caused devastation in Cuba and Haiti, where hundreds of people have died in several tropical storms over the last month.

The Haitian Prime Minister, Michele Pierre-Louis, believes one million people may be homeless, and has called for international help.

The UN says more than $100m (£55.8m) is needed.

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Japan’s economy sees a sharp fall

Japan now seems at real risk of recession

Japan’s economic output has recorded its sharpest quarterly fall in almost seven years as the country appears to be falling into recession.

The world’s second largest economy contracted at an annualized rate of 3% in the April to June quarter, as both domestic demand and exports weakened.

It was the first decline in more than a year, and the biggest since the third quarter of 2001.

The government has called on firms to raises wages to help boost spending.

The Japanese economy, like most around the world, has also been affected by higher energy and food prices.

“It is desirable that income for employed people increases,” said Economy and Fiscal Policy Minister Kaoru Yosano.

“We want company managers to recognize that pay rises would compensate for price rises.”

Last month the Japanese government announced an economic stimulus package worth 11.7 trillion yen ($107bn; £61bn).

A country is generally considered to be in recession when it sees two consecutive quarters of declining economic output.

Venezuela plans Russia navy visit

The exercises will be the first of their in the region

Venezuela says it plans to hold joint naval exercises in its territorial waters with Russian forces in November.

A senior Venezuelan naval officer said four Russian ships would take part in the exercises, which would also involve Venezuelan aircraft and submarines.

Correspondents say the move is likely to raise concern in the US, whose relations with Russia have been soured by Moscow’s recent conflict in Georgia.

Washington already has rocky relations with Venezuela’s President Hugo Chavez.

In July, he called for a strategic alliance with Russia to protect Venezuela from the US.

Caracas and Moscow agreed to extend bilateral co-operation on energy, with three Russian energy companies to be allowed to operate in Venezuela.

Regional first

On Saturday, Venezuela’s Rear Admiral Salbatore Cammarata Bastidas said four Russian ships and 1,000 Russian troops would take part in exercises in Venezuelan territorial waters from 10 to 14 November.

“This is of great importance because it is the first time it is being done (in the Americas),” he said in a statement quoted by the AFP news agency and local media.

President Chavez supported Russia’s intervention in Georgia last month and has accused Washington of being scared of Moscow’s “new world potential”.

Earlier, US Vice-President Dick Cheney launched a furious attack on Russia over the recent conflict in the Caucasus.

Mr Cheney described Moscow’s actions against Georgia as an affront to civilized standards and said it was reverting back to old Soviet tactics of intimidation and the use of brute force.

He added that Russia was also seeking to use its energy resources as a weapon.

Poland’s finest to rock Wembley

Bajm were popular across Eastern Europe before the Iron Curtain fell

Eight of Poland’s top pop and rock acts perform in front of a 10,000-strong crowd at Wembley Arena on Sunday. Billed as the biggest ever Polish music event on foreign soil, what does it mean for Britain’s Polish community?

Crowds of adoring fans will pack Wembley Arena on Sunday to see their favorite superstars perform to a full house.

But it will not be Madonna, Oasis or Jay-Z entertaining more than 10,000 people.

Bajm and Lady Pank may be largely unheard of in the UK but are household names in Poland, where four million viewers are expected to watch the London Live show’s highlights on state channel TVP2.

Tabloid hellraiser

Described as Poland’s answer to Pink Floyd and Red Hot Chili Peppers, their albums have sold three million copies.

Alongside Bracia’s modern grungy-rock and Natalia Kukulska’s soulfull R’n’B, the show even has its own tabloid hellraiser in Doda, who has posed for Playboy and courted controversy by spitting on stage.

Stanislaw Trzcinski, president of promoter STX Records, said: “This is like the O2 Festival, except for Polish music.”

Performing at Wembley is a great honor Natalia Kukulska

Guests on stage include Jan Tomaszewski, the goalkeeper whose heroics at the old Wembley Stadium in 1973 helped secure a 1-1 draw to send Poland to its first World Cup at England’s expense.Mr Trzcinski said: “The name Wembley brings back happy memories for Polish people and it remains a special place, so it was the perfect location.”

Kukulska, 32, has performed with tenor Jose Carreras and duetted with British R’n’B star Lemar at the Sopot festival in Poland in 2005.

She said: “Performing at Wembley is a great honor. I hope I will draw energy from the people who have played there in the past.”

After picking up influences of Michael Jackson and Whitney Houston during a year in the US, she blended them with her own style to sell 2.5 million records at home.

Free tickets

“I’m very excited because this is the first time a lot of artists from Poland are performing abroad together,” she added.

Costing almost £1m to stage, the event has been advertised on 30 London buses and is being beamed back to Poland in high definition, thanks to a 100-strong production crew. Tickets were free to those who registered.

More than one million people voted in an internet talent competition giving bands the chance to perform on a second stage outside the arena, where they will be joined by top acts from the UK and Ireland’s Polish communities.

The show’s arrival reflects the remarkable influx of Poles into Britain.

After the Second World War, the Polish Resettlement Act allowed around 200,000 people to remain in the UK. They were mainly Polish troops, who had fought alongside the British, and their dependents.

By 2001, the census recorded just 60,680 Polish-born people living in Britain.

But since Poland’s accession to the EU in 2004, those numbers have swollen to the 405,000 estimated by the government last year, although the numbers arriving has dropped in recent months.

Appetite for rock

At least 100,000 settled in London, with many basing themselves around established Polish communities in western districts like Hammersmith.

There, the Posk cultural centre boasts the largest library of Polish books outside Poland, a gallery, restaurant and 350-seat theatre.

Supermarkets across Britain have started stocking Polish goods and delicatessens have sprung up in many towns.

THE PERFORMERS Bajm: Six-piece rock outfit, formed in 1978, their 13 albums all went gold or platinum Wilki: Hard-rock band, named “Wolves”, have performed in New York and London Doda (pictured): Daughter of an Olympic weightlifter, gave up athletics to be a pop tearaway Natalia Kukulska: Began singing aged seven and sold 1.5 million records as a child star Kayah: Was a backing singer before her solo career in soul, jazz and R’n’B took off Bracia: Their grunge-rock style made this band – “The Brothers” – favourites with younger fans Monika Brodka: Her soulful voice was inspired by her idols Erikah Badu and Lauren Hill Lady Pank: These punk survivors formed in 1982, playing 400 gigs to promote their debut album

But Piotr Grzeskiewicz, station director at Hammersmith-based Polskie Radio Londyn, said there had been little to feed young migrants’ appetite for rock and pop.

“Hundreds of thousands of Polish people in Britain have limited access to modern Polish culture and this is their best opportunity in many years to see some really big Polish bands,” he said.

Organizers hope many Britons will be at Wembley.

However, Mr Grzeskiewicz said: “The language barrier is huge. Only a few of these bands have played abroad and usually only for Polish fans.”

Warsaw-based bank PKO BP financed the event to promote its central London branch, which opened last December to cater both for migrants and British businesses investing in Poland.

Branch manager Katarzyna Cal said the move demonstrated the growing confidence in Poland’s economy and the number of investors keen to do business in the country.

Meanwhile, Dr Jan Mokrzycki, chairman of the UK’s Federation of Poles, admits he prefers the classical works of Chopin to today’s rock.

Vibrant

But the 75-year-old said the event would help build understanding between the established and newly-arrived Polish communities.

Initial tensions between the groups are diminishing, said the dental surgeon whose mother – a former Nazi concentration camp detainee – brought him to Britain in 1948 to escape communism.

“A combination of their youth, enthusiasm and education and our knowledge of the laws and customs of Britain is helping integration,” said Dr Mokrzycki.

“Cultural events of the old community have been traditional, forged from our experiences of pre-war Poland, so involve mostly classical or folk music.

“The new culture is vibrant with jazz and pop and it’s important younger people have access to that.”

Major ice-shelf loss for Canada

Ward Hunt is the largest of the remnant ice shelves

The ice shelves in Canada’s High Arctic have lost a colossal area this year, scientists report.

The floating tongues of ice attached to Ellesmere Island, which have lasted for thousands of years, have seen almost a quarter of their cover break away.

One of them, the 50 sq km (20 sq miles) Markham shelf, has completely broken off to become floating sea-ice.

Researchers say warm air temperatures and reduced sea-ice conditions in the region have assisted the break-up.

“These substantial calving events underscore the rapidity of changes taking place in the Arctic,” said Trent University’s Dr Derek Mueller.

“These changes are irreversible under the present climate.”

Satellite images show the loss of the Markham Ice Shelf over the last year

Scientists reported in July that substantial slabs of ice had calved from Ward Hunt Ice Shelf, the largest of the Ellesmere shelves.

Similar changes have been seen in the other four shelves.

As well as the complete breakaway of the Markham, the Serson shelf lost two sections totaling an estimated 122 sq km (47 sq miles), and the break-up of the Ward Hunt has continued.

Cold remnants

The shelves themselves are merely remnants of a much larger feature that was once bounded to Ellesmere Island and covered almost 10,000 sq km (3,500 sq miles).

Over the past 100 years, this expanse of ice has retreated by 90%, and at the start of this summer season covered just under 1,000 sq km (400 sq miles).

Much of the area was lost during a warm period in the 1930s and 1940s.

“Long meltwater lakes” were imaged on the Markham shelf in 2005

Temperatures in the Arctic are now even higher than they were then, and a period of renewed ice shelf break-up has ensued since 2002.

Unlike much of the floating sea-ice which comes and goes, the shelves contain ice that is up to 4,500 years old.

A rapid sea-ice retreat is being experienced across the Arctic again this year, affecting both the ice attached to the coast and floating in the open ocean.

The floating sea-ice, which would normally keep the shelves hemmed in, has shrunk to just under five million sq km, the second lowest extent recorded since the era of satellite measurement began about 30 years ago.

“Reduced sea-ice conditions and unusually high air temperatures have facilitated the ice shelf losses this summer,” said Dr Luke Copland from the University of Ottawa.

“And extensive new cracks across remaining parts of the Ward Hunt Ice Shelf mean that it will continue to disintegrate in the coming years.”

Loss of ice in the Arctic, and in particular the extensive sea-ice, has global implications. The “white parasol” at the top of the planet reflects energy from the Sun straight back out into space, helping to cool the Earth.

Further loss of Arctic ice will see radiation absorbed by darker seawater and snow-free land, potentially warming the Earth’s climate at an even faster rate than current observational data indicates.

Energy-hungry Europe warms to Norway

Amid frantic newspaper headlines about the possibility of a new Cold War, more and more governments around Europe are talking about their need for “energy security”.

What most of them actually mean is that they are not sure whether or not to trust the Russians.

Norway remains one of only two major fossil fuel exporters in Europe

There are only two big exporters of fossil fuels in Europe: Russia and Norway, so the choice – for countries without energy reserves of their own or fast depleting them – is limited.

And, undiplomatic as it is to admit it, the Norwegians stand to do very well out of the current political situation.

Officially, a healthy and productive competition exists between the two countries who share a border well above the Arctic Circle.

“We are also partners,” says Norway’s Prime Minister, Jens Stoltenberg, “because both Russia and Norway have an interest in the development of the European oil and gas market.

“And we welcome them into the market, because the market will be bigger if there are several suppliers.”

Mr Stoltenberg was speaking at the opening of an international conference about offshore energy in Stavanger, southern Norway.

Transparency

And, alongside the reassurances to his Russian neighbours, he did hint at his country’s trump card, when asked why the rest of Europe should take Norway as its energy supplier of choice.

Norway offers a reliable energy supply and a stable democracy

“We are a reliable supplier. And we have proved that over many years. And we have a very transparent, open energy sector.”

The head of the conference, ONS Director Kjell Ursin-Smith, was prepared to go even further.

“The situation is very interesting for Norway, of course. We are looked upon as a stable nation, whereas Russia still has a tainted reputation in that respect. So I think we will try to prove that we are a stable producer of oil and gas for Europe.”

The proof of the UK’s commitment to Norway as a gas provider of the future is a massive new pipeline – the biggest engineering project of its kind in the world – known as Ormen Lange.

The pipeline, whose name means “giant serpent” in old Norse will stretch from the Norwegian North Sea fields to Easington on the East Yorkshire coast.

Further afield

Some 745 miles of steel tubing have been painstaking laid up and down the canyons of the seabed, designed to deliver about 20% of the UK’s domestic gas needs for the next 50 years. It came on stream late last year.

The Ukraine issue sent a shiver down the European energy spine and Georgia is a recent episode which will focus a lot of minds. Malcolm Wicks, UK energy minister

The days when Britain could rely on its own reserves to be self-sufficient in oil and gas are long gone – with a current annual depletion rate of about 8% a year – so there is no choice but to look abroad.

Britain has always made a virtue of its lack of political interference in the energy market, preferring to make deciding on a supplier a matter of pure economics and stress the need for “diversity of supply”.

But things might be changing.

“We’re aware of what’s going on now”, says the UK Energy Minister, Malcolm Wicks.

He still stresses the need to source from more than one country, more than one route.

High stakes

But, he adds, referring to the incident in 2006 when Russia turned off gas supplies to its neighbor in order to force higher prices: “The Ukraine issue sent a shiver down the European energy spine and Georgia is a recent episode which will focus a lot of minds.

“I think we have to be – how can I put it? – streetwise, when it comes to issues around energy security. Norway is a great partner to have. It’s a very sophisticated democracy with a great record when it comes to human rights. So the new pipeline is a good piece of democratic politics.”

The proportion of its energy western Europe has to import is likely to rise to about 70% in the coming decades, so the market is guaranteed and the stakes are high.

It remains to be seen whether the big two suppliers – Norway and Russia – will clash or co-operate when it comes to developing what is a potential El Dorado of the North – vast swathes of Arctic territory, largely in the Barents Sea, which new technology is opening up to oil and gas exploitation for the first time.

The disputes have already begun as to who owns what territory. Vast amounts of money are to be made.

Norway has known great wealth for nearly 40 years now, mostly thanks to its fossil fuel resources.

Russia, with an average per capita income still about a tenth the size of that of its tiny Scandinavian neighbor, has not.

And in these days of ‘new’ Russia rediscovering its confidence, reasserting its power in the world, observers of geo-politics can almost certainly expect fireworks.

Blast demolishes landmark towers

Two iconic concrete cooling towers in South Yorkshire have been demolished in a controlled explosion.

Millions of drivers passed the 250ft (76m) towers by the Tinsley viaduct on the M1 at Sheffield over the decades.

At 0300 BST the blast to reduce the “salt and pepper pots” to rubble left part of the north tower still standing but it has since collapsed.

The Highways Agency said the motorway remains closed as planned while safety checks are carried out.

How is a cooling tower demolished?

The blast was watched by several thousand people and the M1 motorway had to be closed from midnight on Saturday, between junctions 32 and 35. It is thought the motorway may reopen on Sunday afternoon.

The towers stood only feet away from the twin-deck Tinsley viaduct, which carries the motorway on the top deck and the A631 on its lower deck.

A joint statement from tower owner E.ON and the Highways Agency said: “The demolition has now been successfully completed.

“The viaduct remains closed and the exclusion zone remains in place as planned to allow safety checks to continue.”

Only part of the north tower fell initially

After the dust settled, about a third of the north tower was still standing but a BBC reporter at the scene said the pile of rubble left after the explosion gradually fell in on itself and reduced significantly in height.

Paul Scriven, leader of Sheffield City Council, said the focus was now on getting traffic moving.

“We need to get the M1 opened as soon as possible,” he said. “We have a Bank Holiday where people will be moving around the country, coming back home, going to see relatives or going to see places.”

Despite campaigns to save the towers, which were the only remnants of the Blackburn Meadows power station, E.ON said it was destroying them as the 70-year-old structures had deteriorated.

Emily Highmore, from E.ON, said preserving the towers would have been very expensive.

“They would require a very, very significant investment and fundamentally speaking we are an energy company and our job is to keep people’s lights on.”

Nowhere else in the world has anyone sought to bring down similar structures that sit so close to a major highway viaduct Arthur Ashburner, Highways Agency

The firm has been given permission to build a £60m biomass power station at the site.

Arthur Ashburner, from the Highways Agency, said: “This demolition is a unique situation and as far as we are aware, nowhere else in the world has anyone sought to bring down similar structures that sit so close to a major highway viaduct.

“We will carry out a series of checks to ensure that there has been no damage to the viaduct, which in itself may take several hours.

“We will reopen the road only when we are entirely satisfied that it is safe to do so.”

Some locals had tried to save the cooling towers and have them turned into art.

Campaigner Tom Keeley said: “You see very few cooling towers that are in quite such a visible position, they’re 12 metres from the M1, and they kind of symbolise not only a gateway to Sheffield and Yorkshire but they also symbolise a gateway to the North.”

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Black hole star mystery ‘solved’

The researchers modelled how molecular clouds are sucked into black holes

Astronomers have shed light on how stars can form around a massive black hole, defying conventional wisdom.

Scientists have long wondered how stars develop in such extreme conditions.

Molecular clouds – the normal birth places of stars – would be ripped apart by the immense gravity, a team explains in Science magazine.

But the researchers say stars can form from elliptical discs – the relics of giant gas clouds torn apart by encounters with black holes.

They made the discovery after developing computer simulations of giant gas clouds being sucked into black holes like water spiralling down a plughole.

“These simulations show that young stars can form in the neighbourhood of supermassive black holes as long as there is a reasonable supply of massive clouds of gas from further out in the galaxy,” said co-author Ian Bonnell from St Andrews University, UK.

Ripped apart

Their findings are in accordance with actual observations in our Milky Way galaxy that indicate the presence of a massive black hole, surrounded by huge stars with eccentric orbits.

The simulations, performed on a supercomputer – and taking over a year of computing time – followed the evolution of two separate giant gas clouds up to 100,000 times the mass of the Sun, as they fell towards the supermassive black hole.

The simulations show how the clouds are pulled apart by the immense gravitational pull of the black hole.

The disrupted clouds form into spiral patterns as they orbit the black hole; the spiral patterns remove motion energy from gas that passes close to the black hole and transfers it to gas that passes further out.

This allows part of the cloud to be captured by the black hole while the rest escapes.

In these conditions, only high mass stars are able to form and these stars inherit the eccentric orbits from the elliptical disc.

These results match the two primary properties of the young stars in the center of our galaxy: their high mass and their eccentric orbits around the supermassive black hole.

“That the stars currently present around the galaxy’s supermassive black hole have relatively short lifetimes of [about] 10 million years, which suggests that this process is likely to be repetitive,” Professor Bonnell explained.

“Such a steady supply of stars into the vicinity of the black hole, and a diet of gas directly accreted by the black hole, may help us understand the origin of supermassive black holes in our and other galaxies in the Universe.”