For the first time, scientists have detected the entire 'birth cry' of a black hole — a region in space that gulps down everything including light — located nearly two billion light years away from Earth. Just like a baby, who cries after taking birth, a black hole, which forms when a sun or a star collapses, emits huge amounts of gamma radiation just after its formation. This is said to be a black hole’s ‘birth cry’.

Indian scientist Sandip Kumar Chakrabarti and Italian scientist Remo Ruffin recorded the entire process of birth lasting 50 seconds after analysing data from Russian satellite Koronas Foton. The satellite had detected the gamma radiation in June 2009. Their findings, which surfaced in October last year, have been reported in scientific journals in the US and Europe.

“Earlier, scientists had recorded such birth cries, but none was complete. While some were contaminated with loud noises, others had only portions of the process lasting around two-three seconds. But we detected the entire cry,” Chakrabarti, head of the department of astrophysics and cosmology at SN Bose National Centre for Basic Sciences in Kolkata, said on Tuesday.

Chakrabarti said since the black hole — named GRB090618 — was nearly two billion light years (one light year is the distance travelled by light in one year) away, it was formed nearly two billion years ago. “The signals reached us only recently.”

The nearest black hole from Earth is the centre of our Milky Way galaxy, 30,000-40,000 light years away. “The energy released by GRB090618 in one second is equal to the energy released by the sun till date since the day it was formed nearly 4.6 billion years ago. We are lucky that it didn’t form somewhere close to our solar system, otherwise the entire earth would have been wiped out within a fraction of a second,” Chakrabarti said.