Astronomers have been able to establish a direct link between supernovae and the formation of black holes and neutron stars, in one of the most intriguing cosmic events ever documented. This discovery helps us understand the evolution of stars, revealing how these bodies arise from massive explosions.
Final part of star formation that leads to destruction
Astronomers have observed the calamitous result of a star that picked the wrong dance partner. They have documented what appears to be a new type of supernova, as stellar explosions are known, that occurred when a massive star tried to swallow a black hole with which it had engaged in a lengthy pas de deux.
The star, which was at least 10 times as massive as our sun, and the black hole, which had a similar mass, were gravitationally bound to one another in what is called a binary system. But as the distance separating them gradually narrowed, the black hole’s immense gravitational pull appears to have distorted the star – stretching it out from its spherical shape – and siphoned off material before causing it to explode.
The explosion occurred about 700 million light-years from Earth. A light-year is the distance light travels in a year, 5.9 trillion miles (9.5 trillion km). The binary system started out with two massive stars orbiting each other as cosmic companions. But one of the two stars reached the end of its natural life cycle and exploded in a supernova, and its core collapsed to form a black hole, an extraordinarily dense object with gravity so strong that not even light can escape.
The fate of the most massive stars
Stars that are at least eight times as massive as the sun appear destined to end their lives with a supernova. Those with a mass at least 20 times that of the sun will form a black hole after the explosion.
An artificial intelligence algorithm designed to scan for unusual explosions in the cosmos in real time first detected the beginnings of the explosion, providing an alert that enabled astronomers to carry out follow-up observations immediately. By the time the explosion was completed, it had been observed by numerous ground-based and space-based telescopes.
Observations of the star dating to four years before the supernova revealed bright emissions that the astronomers believe were caused when the black hole guzzled material sucked off the star. For instance, the star’s outer hydrogen layer appears to have been ripped off, exposing the helium layer below.
Clues reveal the before and after of the explosion
According to the evidence, the interaction between the black hole and the star was prolonged and intense, beginning long before the final collapse. This required the removal of the outer hydrogen layer, which altered the star’s appearance and also influenced the strength and duration of the supernova. This offers important clues to identify other systems that are also about to experience similar events.
The researchers observed bright emissions in the explosion’s aftermath as the black hole consumed leftover stellar debris. In the end, the black hole became more massive and more powerful. Systems grouping two or more companions are quite common. Some of these multiples have a black hole as one of the companions.
The cosmic legacy of stellar destruction
Understanding how black holes form has been expanded, and their study also provides important insights into how these events can be detected earlier. Through residual emissions and brightness patterns, scientists can track the explosion and thus predict how the system will evolve.
Supernovae may be directly linked to the growth of black holes, redefining how the scientific community understands the death of stars. Data from prolonged observations and cutting-edge technology combined to support this discovery and usher in a new era of research into this phenomenon.
GCN.com/Reuters