Marshmallow Star Near a Black Hole: The Edge of Life and Destruction ✦
Scientists simulated the encounter of a Sun-like star with a black hole on an elongated orbit. It turns out the star can either gradually "slim down" by losing mass, or be torn apart in an instant if it gets too close. The flare from such a disruption is visible across vast distances. What fate awaits a star that decides to venture too close to a black hole?
Marshmallow over a campfire: hold it too close — it puffs up and burns; pull it back — it just toasts, losing a bit of crust. That’s how a star like the Sun (made of hydrogen and helium) behaves as it circles a black hole. At the point of closest approach, the hole’s gravity tears gas away. Simulations have revealed a sharp boundary. When the distance falls to about 3.45 critical radii, an avalanche begins. The star loses mass, its outer layers swell, becoming even more vulnerable — and within a few orbits it is destroyed, producing a brilliant flare. At that moment, entropy (a measure of energy dispersal; introduced by Ludwig Boltzmann) grows irreversibly. But if the distance is slightly larger, the mass loss slightly expands the orbit. The star, as if recoiling, pushes itself away from doom. The process becomes slow and prolonged: such pairs can exist for decades. This links two scenarios — quiet feeding of the hole and catastrophic disruption. Predictions will be tested with the help of spectroscopy, photometry, and the James Webb Space Telescope. The ideas of Karl Schwarzschild and Subrahmanyan Chandrasekhar about matter in strong gravity are now being realized in computer models.
🎯 The destruction of a star by a black hole is sometimes called 'spaghettification'. In the described simulations, the star not only stretches into a thread but also first puffs up several times, like a marshmallow over a fire.