The discovery may prove key to fundamental physics and to help calculate the age of the Universe.
Astrophysicists from the University of Copenhagen have observed a ‘perfect’ explosion in the space that formed a completely symmetrical sphere, which —they say— “does not make sense,” reports the educational institution on its website.
It is an explosion a thousand times brighter than that of a classical nova and is known as kilonovaa little-studied astronomical event that occurs when two neutron stars merge.
The first observation of a kilonova was observed in 2017, allowing scientists to collect the first data on this type of phenomenon.
Until now it was thought that kilonovae usually form a flattened cloud, so its spherical shape has caused perplexity among scientists.
What are neutron stars?
Neutron stars are extremely compact and are made up mostly of neutrons. They are usually only about 20 kilometers in diameter, but they can weigh almost twice as much as the Sun. Thus, a teaspoon of neutron star matter would weigh as much as Mount Everest.
Given its small size and high density, a neutron star can have magnetic fields. a million times stronger than the strongest magnetic fields on Earth. A neutron star is one of the possible final stages of stellar evolution.
“It should have a flattened shape”
“We have two supercompact stars that orbit each other 100 times per second before collapsing. Our intuition, and all previous models, say that the explosive cloud created by the collision must have a flattened shape and quite asymmetrical“, says Albert Sneppen, a doctoral student at the Niels Bohr Institute and first author of the study published in the journal Nature.
However, this kilonova was completely symmetrical and close in shape to a perfect sphere.
“Nobody expected the explosion to look like this. It doesn’t make sense for it to be spherical, like a ball. But our calculations clearly show that it is. This probably means that the kilonova theories and simulations we’ve been considering for the last 25 years lack major physics“, says Darach Watson, associate professor at the Niels Bohr Institute and second author of the study.
A New Key to Fundamental Physics
The discovery may provide a new key to fundamental physics and help calculate the age of the Universe.
The call ‘cosmic distance ladder‘ is the method used today to measure the speed with which the Universe is expanding, and consists of calculating the distance between different objects in the universe.
“If they are bright and mostly spherical, and if we know how far away they are, we can use kilonovae as a new way of measuring distance independently, a new kind of cosmic ruler,” Watson suggests, stressing that this is done by they need data from more kilonovae. In this sense, he hopes that the observatories will detect many more in the coming years.