clash two neutron stars European astrophysicists discovered that there was an explosion in the shape of a perfect sphere. It remains a mystery, as they say, how this happens.

The corresponding publication in the journal Nature was made by researchers from Denmark, Germany, Great Britain, Finland and Israel, led by scientists from the University of Copenhagen. The discovery concerns a powerful kilonova explosion, first detected in 2017 by the gravitational wave observatories LIGO (USA) and Virgo (Europe) in a galaxy 140 million years from Earth in the direction of the constellation Hydra.

A follow-up observation of the outburst, named AT2017gfo/GW170817, with the European Southern Observatory (ESO) Very Large Telescope (VLT) in Chile showed that it was perfectly symmetrical and perfectly spherical, which was unexpected.

“Doesn’t Make Sense”

“No one expected the explosion to be like this. It doesn’t make sense that it’s as spherical as a ball. But our calculations clearly show that it is. This probably means that in the theories and simulations of the kilonovae that we have done over the past 25 years old, missing some important physical aspects,” said Associate Professor Darra Watson from the Niels Bohr Institute in Copenhagen.

“The most likely way that an explosion could become spherical is by releasing a huge amount of energy from the center of the explosion and then creating a shape that is usually not symmetrical. Thus, the spherical shape tells us that the core of the explosion probably contains a lot of energy, which was not predicted, ”said lead researcher Albert Schneppen.

Neutron stars (pulsars) are highly condensed stars composed mostly of neutrons and are typically only 20 kilometers in diameter, yet their mass is almost twice that of the Sun. A teaspoon of neutron star matter weighs about the same as Mount Everest.

Collision of two neutron stars

(Source: NASA Goddard Space Flight Center/CI Lab) pic.twitter.com/zq7kBQI2jv

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When two neutron stars collide, a kilonova explodes, as they first merge into a single massive neutron star, which then collapses into a black hole. Theoretically, kilonovae have been predicted since 1974, but they were first clearly detected in 2013.

^{According to information from APE – MEB}