Mystery of vanishing stars: Black holes without supernovae revealed

In recent years, astronomers have become interested in the phenomenon of stars that seem to disappear from our field of view without a clear cause. The VASCO project from 2019, aimed at cataloguing instances of stars that have vanished over the past 70 years, found around 100 such objects. Typically, stars do not disappear overnight but gradually fade away like Betelgeuse, for example, or explode as a supernova, ultimately collapsing into a black hole or neutron star.

An international team led by astrophysicist Alejandro Vigna-Gómez from the Niels Bohr Institute in Denmark and the Max Planck Institute for Astrophysics in Germany conducted research that sheds new light on the entire phenomenon. Experts in the article, published in the journal Physical Review Letters, suggest that stars of appropriate mass can collapse directly into a black hole without a supernova explosion phase. Previous knowledge about the formation of black holes always assumed the violent phenomenon of a supernova as an intermediate stage.

According to IFL Science, evidence for this has been found in a binary system called VFTS 243 in the Large Magellanic Cloud on the outskirts of the Milky Way. It consists of a black hole and a companion star, which orbit each other every 10 days. This system shows no signs of a supernova explosion, which, according to known models, should accompany the formation of a black hole. This may explain the disappearance of stars for unexplained reasons. Despite these promising observations, experts emphasise the need for further research to confirm their assumptions.

The research results suggest that the disappearance of some stars could be a direct result of fully collapsing into black holes, in a process where the emission of neutrinos and, to a lesser extent, gravitational waves dominate over the massive ejection of matter. "Our observations have allowed us to understand better how black holes can form through complete collapse without the star exploding as a supernova," explained Alejandro Vigna-Gómez, one of the study's authors, in a press release.

Astronomers have observed such disappearances so far, which brings us closer to understanding some of the most mysterious phenomena in the universe. This work, as emphasised by Professor Irene Tamborra, from the Niels Bohr Institute and co-author of the study, represents an important confirmation of theoretical models. It is expected to become a key reference point in future studies on the evolution of stars and their collapse.