Scientists spot star collision, sparking powerful cosmic burst

Scientists have discovered a giant explosion as far as three billion light-years away from Earth coming from an old galaxy — believed to be sparked by the collision of two neutron stars present in a packed galactic environment near a supermassive black hole, reported Reuters.

This ancient galaxy had stars as old as several billion years.

The scientists in their research — published in the journal Nature Astronomy — believed that the two destructed stars were the neutron stars having a mass of our sun with a space of only size similar to a city.

Astronomer and the lead author of the study Andrew Levan of Radboud University in the Netherlands said: "In order to explain the gamma-ray burst, it has to have been a compact star, so not one like the sun."

"Gamma-ray bursts are the most powerful explosions in the universe. They release more energy per unit of time than any other known cosmic phenomena."

A co-author and astrophysicist Wen-fai Fong of Northwestern University in Illinois maintained: "So they are really superlative in their properties. Their name comes from the first type of light that we see, gamma rays, but they actually emit across the electromagnetic spectrum."

The researchers opined in their study that immense gravitational forces exerted by the black hole may wreak havoc, causing a disturbance in the motion of nearby stars and other objects and increasing the chances of collisions "similar to a demolition derby".

"Most stars in the universe die in a predictable way, which is just based on their mass. This research shows a new route to stellar destruction," Levan said.

"The idea that stars also can die through collisions in extremely dense regions has been around since at least the 1980s. So we've been waiting for 40 years for the signatures to be found observationally," Levan said.

"The galaxy is what we call 'quiescent' — a galaxy that is not actively forming stars at a high rate and is past its heyday," Fong said.

"These quiescent galaxies are very massive and have built up large supermassive black holes in their centres, making them a perfect breeding ground for stellar collisions."

"You certainly wouldn't want a front-row seat to one of these events," Levan said.

"But, if you were close enough, you would see the two neutron stars get ever closer until their gravity deforms them and they begin to shred," Levan added.

"Then the cores of the stars would merge to make a black hole, surrounded by a disc of the remaining material. A fraction of a second later, this material would flow into the black hole, and a jet of material moving at 99.99% of the speed of light would launch," representing the gamma-ray burst.