A rare supernova explosion has revealed insights into the origins of the universe's history.

Astronomers interpret the periodic table in their own way: they understand the cosmic origin of all chemical elements, except of course for those created by humans. The very first atoms in the universe were hydrogen atoms, which makes perfect sense as they have the simplest structure — a proton and an electron. To this day, hydrogen accounts for the overwhelming majority of all matter in the universe.

As stars and entire galaxies formed from this hydrogen, processes began that created increasingly complex atoms. For instance, oxygen, sodium, and aluminum are considered products of supernova explosions, while a significant portion of gold and platinum formed during the collisions of neutron stars. Thus, the diversity of chemical elements in the periodic table is the result of billions of years of evolution in our galaxy.

Recently, space researchers gained the opportunity to observe the universe as it was in its early stages: when, besides hydrogen and slightly more complex helium, there was virtually nothing else. Interestingly, everything heavier than these two elements is referred to by astronomers as "metals."

An international team of astronomers led by researchers from Ohio State University (USA) reported in The Astrophysical Journal about an unusual supernova explosion they managed to observe — event SN 2023ufx in a dwarf galaxy located 215 million light-years away from us. What makes it unusual is that in this exploded star and its entire "home" galaxy, very few of these so-called metals are detected, meaning there is little present beyond hydrogen and helium. From a chemical perspective, this is essentially akin to the primordial conditions of the universe.

Astronomers noted that all small galaxies are like small towns: extreme events are less frequent there. Not many stars explode, and they collide infrequently, which is why there are few "heavy" elements. Therefore, they can serve as examples of what our Milky Way galaxy was like in its early stages.