The Birth of a Gravastar: How a Star Escapes a Black Hole ⚡ экспресс
What if a black hole isn't the only ending for a dying star? Scientists have shown how, during the collapse of a dust cloud, a tiny region of repulsive energy can emerge at the center. It grows, slows down near the event horizon, and freezes, forming a gravastar — a stable object without a hole. Could such ghost stars already exist out there?
A dying massive star usually shrinks into a black hole—a trap from which even light cannot escape. But another finale is possible: a gravastar—a bubble of dark energy, the mysterious force pushing the cosmos apart.
Simulations of a collapsing cloud revealed: deep in the center, a tiny nugget of dark energy is born. It inflates, like a soap bubble in a vacuum. Upon reaching the critical radius where a black hole would normally appear (first calculated by Karl Schwarzschild), the expansion halts. Infalling matter hangs suspended on the bubble—a stable gravastar is born. The surprise: inside, space stretches as rapidly as in the first moments after the Big Bang—a whole mini-universe beneath the shell.
The trick doesn't always work. The star must be sufficiently 'fluffy': its mass-to-radius ratio (in special units) must be less than 3/8. Otherwise, collapse into a black hole is inevitable.
🎯 Inside a gravastar, space expands like a newborn Universe—a miniature cosmos hidden from us by a glowing shell.