Pre-Sputnik Transient Brightenings in the Palomar Observatory Sky Survey Show Correlation with Nuclear Tests and UAP Reports

To the point

Bruehl and Villarroel show that very short, star-like brightenings seen in Palomar Sky Survey plates from 1949–1957 are real transient events that were about 45% more likely to occur on dates within nuclear-test windows, suggesting a possible link to atmospheric effects from nuclear blasts or, less likely, unidentified aerial phenomena, though the absence of streaks argues against simple Cherenkov light and further work is needed to determine the cause.