This ‘out of the world’ event ,announced on 2 September 2020 in Physical Review Letters, is by far the biggest event ever detected via gravitational waves.The collision released about eight times the energy in our sun in just a fraction of second!

EVERYTHING IS NEW AND UNEXPECTED ABOUT THIS BLACKHOLE COLLISION!

The final black hole of about 142 solar masses is the first ever found in the intermediate mass range.It was formed when the two black holes of 66 and 85 solar masses spiralled into each other.But something is even more surprising with the starting black hole of 85 solar masses.Theoretically,it should not even exist due to a phenomenon called ‘pair-instability’.

The event,happening more than seven billion years ago,was detected by LIGO and Virgo on 19 May 2019 at 8.30 am IST as gravitational waves passed through earth.The signal is stored in the form of sound wave called ‘chirp’ and is named GW190521. GW stands for gravitational waves, followed by the date of detection.We describe gravitational waves as ripples in the fabric of space-time that propagate at the speed of light.These waves are produced by accelerated masses.When two massive black holes, spiraling each other,collide they release huge amount of energy in the form of gravitational waves.

Earlier, scientists had found black holes tens of times more massive than our sun and supermassive black holes million to billions times more massive than our sun but this event has confirmed the presence of intermediate mass blackholes.

Conventionally, stars having mass around 85 solar masses should undergo ‘pair-instability supernova‘ – leaving behind no black hole or neutron star.Some scientists believe that such black hole could have formed from the merger of two smaller ones while others think that the black hole grew to its present size by swallowing matter around it.To solve this mystery,scientists are waiting to detect more events like this and squeeze out the best model.

What, according to you, can be the best explanation?

Credits: 📸 MARK MEYERS, DEBORAH FERGUSON, KARAN JANI, DEIRDRE SHOEMAKER, PABLO LAGUNA/GEORGIA TECH, MAYA COLLABORATION.

References :