We now know more about stellar death by black hole.
A group of astrophysicists have thrown stars at black holes in a series of simulations.
The study combines Einstein's theory of general relativity with realistic models of the densities of main-sequence stars. The results will help us understand what is happening when we see flares of light from black holes.
The simulations support a paper that was published last year.
When a star is too close to a black hole, things can get violent very quickly. The star is pulled apart by the tidal forces of the black hole, due to the extreme gravity of the hole.
When a star gets close to a black hole, material is stripped from the star, which is called a tidal disruption event.
There is no escape in the worst-case scenario for the star. The star's material is eaten by a black hole like a spaghetti noodle.
Not every encounter between a black hole and a star ends this way. Some stars are still alive. The goal of the simulations was to find out what factors contributed to a star's survival.
The team created six virtual black holes with a mass between 100,000 and 50 million times that of the Sun. Each of the black holes had encounters with eight main-sequence stars with a mass between 0.15 and 10 times that of the Sun.
The initial density of the star was the main factor that contributed to a star's survival. The denser the star, the more likely it is to encounter a black hole. The stars with the highest density are yellow.
The proportion of the star's mass that is lost can be described with a simple expression, and the team found that partial disruptions occur at the same rate as total disruptions.
The researchers said that future research will help model the effects of these encounters.
This will show what can happen to a star after it encounters a black hole, whether it continues along the main sequence or becomes a stellar remnant, and if it will continue in the vicinity of the black hole to meet total disruption at a later date.
The Astrophysical Journal published the paper in 2020.
