Delayed Radio Emission Following Stellar Disruption
When a star ventures too close to a supermassive black hole, tidal forces shred it, producing a brief, bright flare that was long thought to mark the end of the event.
Using the Very Large Array, researchers have monitored dozens of such tidal‑disruption events and found that many black holes emit additional radio outbursts months or even years later. The delayed signals arise when part of the accreted material is expelled back into space, creating streams of radio light.
- Post‑flare radio activity can persist from several months up to several years.
- The phenomenon is colloquially described as a “burp” of the black hole.
- Even relatively quiescent giants in the Milky Way display this behavior.
These observations allow scientists to track changes in a black hole’s feeding rate in real time and to study the complex interplay between infalling and outflowing matter.
The findings suggest that supermassive black holes are far more dynamic and active than previously believed, opening new avenues for long‑term studies of tidal‑disruption events.