Astronomers just saw light moving nearly four times faster than its own 'universal speed limit' inside a distant nebula.
April 2, 2026
Original Paper
On the variability of the reflection nebula Van den Bergh 27 surrounding RY Tau
arXiv · 2604.00964
The Takeaway
While nothing can actually break the cosmic speed limit, certain geometric alignments allow light to sweep across gas clouds so fast it creates a faster-than-light illusion. Watching this specific 'light echo' move allows scientists to map the 3D environment surrounding a young star in real-time.
From the abstract
We present an analysis of the short- and long-term optical variability in Van den Bergh 27 (vdB 27), the reflection nebula surrounding RY Tau. The observed variations form a light-echo pattern, with apparent propagation speeds varying across different regions of the nebula and reaching up to approximately 3.6 c, consistent with geometric projection effects. The observed variations in nebular surface brightness are consistent with changes in illumination from the central star.