Two black holes merge into one giant mass bigger than the Sun

Daily Mail​

2 days ago

Two black holes have merged together, experts have found, resulting in an enormous mass more than 225 times the mass of our Sun.
The signal, detected through gravitational waves, is called GW231123 and comes from between two and 13 billion light-years away.
In addition to their high masses the black holes merging together are also spinning rapidly, around 400,000 times the Earth's rotation speed.
'This is the most massive black hole binary we've observed through gravitational waves, and it presents a real challenge to our understanding of black hole formation,' Professor Mark Hannam, from Cardiff University, said.
'Black holes this massive are forbidden through standard stellar evolution models.
'One possibility is that the two black holes in this binary formed through earlier mergers of smaller black holes.'
Black holes are regions in space where gravity is so incredibly strong nothing – not even light – can escape. They are among the most mysterious cosmic objects, with huge concentrations of matter packed into very tiny spaces.
This black hole merger was detected by both the LIGO Hanford Observatory in Washington and the LIGO Livingston Observatory in Louisiana.
But signal they detected only lasted 0.1 seconds – making it especially challenging to interpret.
To date, approximately 300 black hole mergers have been observed through gravitational waves.
Until now the most massive confirmed black-hole binary had a much smaller total mass of 'only' 140 times that of the Sun.
The high mass and extremely rapid spinning of the black holes in GW231123 pushes the limits of both gravitational-wave detection technology and current theoretical models, experts said.
'The black holes appear to be spinning very rapidly - near the limit allowed by Einstein's theory of general relativity,' Dr Charlie Hoy, from the University of Portsmouth, explained.
'That makes the signal difficult to model and interpret. It's an excellent case study for pushing forward the development of our theoretical tools.'
While the 'merged' black hole is undoubtedly huge, others detected using other instruments have been found to be much bigger.
Last year, astronomers led by the University of Cambridge used the James Webb Space Telescope to detect a black hole in the early universe that was 400 million times the mass of our Sun.
And at the other end of the scale, scientists say there could be thousands of tiny black holes hiding in our homes.
Instead of the star-swallowing, galaxy-churning supermassive black holes, these are microscopic singularities no larger than a hydrogen atom.
According to some calculations, as many as 1,000 could be passing through every square metre of the planet each year - with nobody even realizing they're there.
The discovery of the black hole merger will be presented at the 24th International Conference on General Relativity and Gravitation in Glasgow.