Astronomers are witnessing the birth of a binary star system for the first time

The researchers observed a unique type of stellar explosion on the periphery of a spiral galaxy 920 million light years from Earth. They believe that the unusual explosion is actually a supernova that has resulted in the death of a massive star. However, the explosion is surprisingly weak and fades quickly, suggesting that the star also has an invisible companion. The companion star removes most of the star's mass and eventually creates a compact neutron star binary system – a system where two stars are in orbit.

A supernova occurs in the last stages of a star's life. When a massive star falls short of nuclear fuel, its nucleus collapses and then bursts into an explosion. These explosions are extremely powerful and bright and leave behind dense neutron stars, the size of a city but containing more mass than the Sun.

Usually, these events release material losses. However, the explosion, dubbed iPTF 14gqr, ejected the material only on one fifth of the Sun's mass. The findings of the study are based on observations from the Global Observer Transients Happen (GROWTH) project, conducted by Caltech.

"We witnessed the collapse of the nucleus of this massive star, but we found a remarkably low mass of ejected mass," said Mansi Kasliwal, the project's principal investigator. the first time, we have convincingly witnessed the collapse of the nucleus of such a massive star that has no matter. "

The explosion implies that the star must have already had a lot of material or its core would never have been big enough to collapse. In both cases, it lacks mass. The researchers suggest that the mass must have been stolen by a compact star, such as a white dwarf, a neutron star or a black hole. These stars will eventually merge and form a narrow binary system. In fact, the merger of two neutron stars was observed for the first time in August 2017 by a team of Carnegie and UC Santa Cruz astronomers.

The unusual event was initially spotted by the Palomar Observatory. Follow-up observations with other telescopes allowed the researchers to draw a conclusion.

"Discoveries like this show how important it was to create a theoretical astrophysics group at Carnegie," said Anthony Piro of Carnegie. "By combining observations and theory, we can learn a lot more about these extraordinary events."