A team from the Hebrew University of Jerusalem, led by researchers from the Racah Institute of Physics, has employed sophisticated simulations to recreate the violent destruction of a star by a supermassive black hole. This study, published on January 17 in the journal
Nature, sheds new light on tidal disruption events (TDEs) where a star, getting too close to a black hole, is literally torn apart.
Screenshot of a simulation showing how a star is torn apart by a black hole during a tidal disruption event.
Credit: Elad Steinberg
A TDE occurs when the orbit of a star gets too close to a supermassive black hole, whose mass is millions to billions of times greater than that of the Sun. The black hole's gravitational force then creates colossal tidal forces within the star. This influence causes the star to stretch vertically and compress horizontally, turning it into a long strand of stellar plasma, in a process known as "spaghettification."
This spaghetti-fied plasma, as it falls back towards the black hole, is heated by a series of shock waves. This leads to an extremely bright outburst that can outshine the combined light of all the stars in a galaxy for weeks, or even months.
For the first time, the simulation by Elad Steinberg and Nicholas Stone from the Racah Institute of Physics has recreated the entirety of these events, from the star's capture by the black hole to the peak of the TDE outburst. They uncovered a previously unknown type of shock wave occurring during the TDE, revealing that these events dissipate energy more rapidly than scientists previously thought.
This discovery suggests that the brightest periods of the TDE are powered by these shock waves and the associated energy dissipation. These findings could help astronomers utilize TDEs to uncover properties of supermassive black holes, such as their mass and spin rate, and to test the limits of Einstein's theory of general relativity.
Astronomers will continue to delve into the mechanisms of these powerful shock waves thanks to real-life observations of these violent encounters between supermassive black holes and doomed stars.