A growing black hole develops a unique glowing ring that brightens and moves as it eats matter.
March 31, 2026
Original Paper
Gravitational lensing and observational features of a dynamic black hole
arXiv · 2603.27606
The Takeaway
Simulations of 'dynamic' black holes show that during feeding frenzies, a new type of light ring appears that isn't seen in static models. This ring actually contracts and glows brighter as the black hole consumes more matter, providing a potential way to 'watch' a black hole grow in real-time.
From the abstract
In this work, we investigate the gravitational lensing effects and the dynamic evolution of the shadow of Vaidya black holes by employing backward ray-tracing techniques. Within the celestial sphere framework, the black hole shadow exhibits a complete evolutionary sequence, transitioning from an initial stable configuration through continuous expansion to a final static state. Notably, during and after the active accretion phase, a distinct lensing ring emerges outside the shadow. Extending this