A burst of gamma rays released more energy in half a second than the sun would produce in 10 billion years.
Scientists have discovered a short burst of gamma radiation from the collision of two neutron stars, which releases more energy in half a second than the Sun in 10 billion years of its life. It is teported by New Atlas.
Collisions of neutron stars are some of the most impressive cataclysms in the universe. In a matter of seconds, they release more energy than the sun will generate in its entire long life. Such an explosion is a thousand times more powerful than the outburst of a new star (which in itself is by no means a mere firecracker), therefore it is called a kilonova.
In the Universe there are quite a few flares of a different nature, and astronomers rarely manage to prove that they observed exactly the collision of neutron stars.
The first event, which definitely could not be anything else, was recorded only in 2017 . Since then, several more kilonova , or, as cautious scientists prefer to put it, kilonova candidates have been discovered. However, the GRB 200522A event, which the researchers report about in the current scientific article, is something special.
The flare, dubbed 200522A, occurred 5.47 billion light years from Earth and was 10 times brighter than the light of a new neutron star.
Gamma-ray bursts are extremely high energy phenomena that occur during events such as a supernova explosion. Such bursts can last up to several hours, but if their lifetime is less than 2 seconds, they are called short bursts of gamma radiation.
Until recently, these short bursts were thought to arise either from the collision of two neutron stars generating enormous amounts of energy before collapsing into a black hole, or from the collision of a neutron star with a black hole absorbing the first.
The mainstream theory was that either scenario would end up with a black hole. But NASA’s Neil Gerels Swift Observatory detected the 200522A flare.
Short gamma-ray bursts have been observed across the entire electromagnetic spectrum, from radio emission to X-rays. The Hubble Telescope found that the detected flash did not disappear as expected.
Instead, it glowed in the infrared light 10 times brighter than theory predicted. According to scientists, this means that instead of forming a black hole, the collision of neutron stars produced a new star called a magnetar.
Neutron stars are stars that have about the same mass as the Sun, but their diameter is only about 20 km.
The peculiarity of the 200522A flare was that its brightness was at the very bottom of the supernova scale. Instead of forming a black hole, neutron stars merged like their magnetic fields to form a magnetar – a massive star with an equally massive magnetic field.