Astrophysicists Make a Groundbreaking Discovery: For the First Time, They’ve Observed the Creation of Atoms During an Explosive Cosmic Event

“For the first time, we see the creation of atoms, we can measure the temperature of the matter, and we can see the microphysics in this remote explosion,” Rasmus Damgaard, an astrophysicist and researcher at the Cosmic Dawn Center (DAWN) at the Niels Bohr Institute in Denmark, said in a recent statement. He used these words to describe the importance of one of the most spectacular cosmic phenomena captured by NASA’s Hubble Space Telescope in recent years.

Damgaard and his colleagues at the DAWN center studied the collision of two neutron stars, which triggered the formation of the smallest black hole observed to date. Remarkably, the Hubble Space Telescope and other instruments detected this event despite it occurring 130 million light-years away from Earth. This analysis could help scientists better understand how elements heavier than iron are formed, given that these elements can’t condense inside stars through nuclear fusion reactions.

The collision and subsequent fusion of two neutron stars is known as a kilonova, an extraordinarily energetic event capable of emitting as much light as several hundred million stars simultaneously. It’s difficult to fathom the scale of this phenomenon. Most astonishingly and for the first time, astrophysicists studying this kilonova have observed the processes that lead to the creation of atoms, as explained in a paper published in Astronomy & Astrophysics.

Neutron Stars Are One of the Most Exciting Objects in the Cosmos

Neutron stars aren’t always solitary. Sometimes, one of them is part of a binary system alongside a “living” star. Under the right conditions, the “living” star can also become a neutron star. In this scenario, the binary system consists of two neutron stars that orbit each other. Over time, they lose angular momentum, causing their orbits to gradually bring them closer together. Eventually, when they’re close enough, gravity takes over, and the two neutron stars are destined to collide.

This powerful cosmic event results in the emission of electrons and neutrons that begin to spin around the massive object created by the collision of the two neutron stars. Ultimately, this object collapses at high speed, leading to the formation of a black hole.

According to DAWN scientists, this sequence of events has occurred in the galaxy NGC 4993. As mentioned earlier, neutron stars serve as the starting point for the process. It’s truly fascinating.

The remnant of a star, after it’s expelled its outer layers into the stellar medium during a supernova, can have a mass greater than 1.44 solar masses (a threshold known as the Chandrasekhar limit, named after Subrahmanyan Chandrasekhar, the Indian astrophysicist who calculated it). If this occurs, the stellar remnant will further collapse to form a neutron star.

Just moments before the supernova occurs, the iron core of a massive star experiences intense pressure from the upper layers of the star and the relentless force of gravitational contraction. These conditions trigger quantum processes that lead to significant changes in the structure of matter. This can cause the iron in the star’s core, which is subjected to high temperatures, to undergo photodisintegration. Photodisintegration is driven by high-energy photons, which are a form of energy transfer known as gamma radiation.

These extremely high-energy photons disintegrate the iron and helium in the star’s core, forming alpha particles consisting of two protons and two neutrons. Alpha particles are helium nuclei devoid of their electron shells and carry a positive charge. Additionally, a process known as beta capture occurs. It causes the electrons in the iron atoms to interact with the protons in the nucleus, neutralizing their positive charge and producing additional neutrons.

During this process, the initial matter, composed of protons, neutrons, and electrons, transforms so that it becomes entirely made up of neutrons. This transformation occurs because protons and electrons interact through electron capture, forming additional neutrons. From that moment on, the star is no longer composed of ordinary matter. Instead, it has turned into a massive structure made entirely of neutrons.

However, once the star reaches this state, there’s a mechanism that allows this ball of neutrons to counteract the immense gravitational pressure pulling it inward. The phenomenon that keeps the neutron star in equilibrium is the Pauli exclusion principle, a quantum effect.

Roughly speaking, the principle established by Austrian physicist Wolfgang Ernst Pauli in 1925 states that two fermions within the same quantum system can’t occupy the same quantum state. Fermions include quarks, which are the elementary particles composing protons and neutrons in atomic nuclei, as well as electrons. To understand the implications of this principle, consider how the inability of two neutrons to occupy the same position generates the necessary pressure that helps maintain the equilibrium of neutron stars.

The Pauli exclusion principle leads to one of the most astonishing characteristics of neutron stars: their density. Despite having an average radius of about 6 miles, neutron stars have an extraordinarily high mass. When compared to stars on the main sequence or even to white dwarfs, neutron stars are quite small. The concentration of so much mass in a limited space means that a fragment of a neutron star measuring about 0.06 cubic inches weighs approximately one billion tons. It’s truly remarkable that a piece of matter the size of a sugar cube can possess such an immense weight.

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