Ancient stars reveal the time when gravitational waves land on Earth

For the first time astronomers discovered gravitational waves that bounced back from a collision between two black holes more than a billion years ago.

Illustrations of binary star systems orbiting each other.(Photo: ESO).

According to the scientists' model published June 22 in Nature, black holes were once massive stars orbiting each other. These giant stars have 96 times the mass and 60 times the Sun. They formed about two billion years after the Big Bang . When the two stars turn off, they turn into black holes and continue to orbit. Finally, two spiral stars and merged into one.

Cosmic tremors caused by black holes affect the Earth on September 14, 2015. This gravitational wave was discovered by the Interfering Laser Observatory (LIGO) in Louisiana, USA. This is the only evidence of the existence of this black hole, according to National Geographic.

The model shows that the black hole merger is the largest source of gravitational waves. It produces a greater amount of gravitational waves than many of the gravitational waves produced by collisions between neutron star pairs or between black holes and neutron stars.

If the black hole merges correctly, LIGO expects another black hole merger to occur in 2020. This will give astronomers the opportunity to study the entire number of black holes. . They will also learn about the evolution of stars from their remnants.

The model of the September 14 event helps explain the unusual size of black holes. " The model shows that this is an unusual pair of cosmic stars , " said Richard O'Shaughnessy of the Rochester Institute of Technology. This pair of stars mainly consists of hydrogen and helium clouds . These two basic materials help star pairs to be larger than most newly formed stars.

Newly born stars are affected by the heavy elements created by previous stars. Over billions of years, the rapid disintegration of stars limits the size of black holes formed after the star shuts down.

Some stars expand and become black holes after turning off. The rest revolved around each other for about 10 billion years. They generate energy in very small gravitational waves. About 1.4 billion years ago, these stars came together and created a death spiral. This collision created the largest amount of energy in history.

" We cannot know the cause of black hole mergers unless it is a special case. But we hope to classify their origins ," said Ilya Mandel, the astrophysicist of Dai. Study Birmingham, England, share.