Researchers revisited the 1950s Palomar sky survey plates to hunt for fast astronomical transients. Critics have long argued that brief flashes captured on the glass could simply be plate defects. The new analysis, led by Ivo Busko, demonstrates that genuine transients display a distinct coma aberration pattern, a signature of off‑axis point sources passing through the telescope optics. Their findings also suggest a pathway for re‑evaluating other disputed detections.

By measuring the coma curvature across dozens of candidate images, the team proved that the distortion matches predictions from the original Schmidt telescope design. Artificial artifacts such as scratches or emulsion bubbles lack this optical geometry, so they cannot mimic the observed pattern. This methodological check restores confidence that at least some historic flashes represent real celestial events. Furthermore, the method quantifies the aberration angle, reinforcing the match to the telescope’s field curvature.

Although the plates alone cannot identify the physical source of the light, the optical‑signature test eliminates instrumental bias, allowing astronomers to revisit archival data with a reliable filter. The approach could be applied to other large photographic collections, potentially uncovering missed transient phenomena and informing modern time‑domain surveys about the prevalence of short‑lived events. By integrating this technique into automated scans, future projects can flag promising candidates for rapid follow‑up with contemporary instruments.