Astrophysicists determined that neutron stars have various internal structures depending on their mass, much like chocolate bonbons.
Astrophysicists who were creating models of the interior of neutron stars determined that these compact bodies are composed of various internal structures depending on their mass. That is why they say that these bodies are like a kind of “cosmic chocolate bonbons” .
In research published in The Astrophysical Journal Letters , the team in charge explains that it built millions of models of neutron stars to discern their inner workings, which is extremely difficult to study because their enormous gravitational fields have the ability to break down bodies down to the subatomic level.
Neutron stars and their resemblance to chocolate bonbons
The researchers mentioned that the lightest neutron stars (with a mass about 1.7 times that of our Sun ) must have soft mantles and rigid cores. On the contrary, the heaviest ones are opposite to what was previously explained. Luciano Rezzolla , an astrophysicist at the Institute for Theoretical Physics who led the research, compared the structure of stars to chocolate bonbons.
“Light stars resemble those pralines that have a hazelnut in their center surrounded by soft chocolate, while heavy stars can be considered more like those pralines where a hard shell contains a soft filling,” Rezzolla said in a statement sent out. Goethe University in Frankfurt, Germany .
The authors of the research created models based on a million possible scenarios to capture the composition of neutron stars based on their mass, pressure, volume, temperature and astronomical observation of said objects. This method is crucial to determine how these stars are formed, since only a few instruments are capable of mimicking their intense physics.
The Findings of Neutron Stars
To analyze the consistencies of stars , the researchers modeled how the speed of sound would travel through these bodies. Sound waves are also used to understand the internal structure of planets, as the InSight Mars lander did .
“What we have shown, by building millions of equation-of-state models (from which the speed of sound can be calculated), is that maximally massive neutron stars have a lower speed of sound in the region of the nucleus than in their outer layers. This points to some material change in their nuclei, such as a transition from baryonic matter to quark matter, ” Christian Ecker , an astrophysicist at Goethe University , told Gizmodo .
On top of all this, the researchers also found that all neutron stars are probably about 12 km in diameter, regardless of their mass. This measurement is less than half of what was discovered in 2020, according to which the typical neutron star was about 22 km in diameter. Despite that size, the average mass of neutron stars is around half a million Earths .
While these discoveries offer insight into the diversity of neutron stars in terms of their consistency, the researchers did not find the ingredients of the stars or how they work with each other. Some suspect that neutron stars are neutrons to the bottom. Others believe that the centers of the stars are factories of exotic particles that have not been identified until now.