The Enigma of the Disappearing Stars: An Unsolved Astronomical Mystery from 1952

On a seemingly ordinary night on July 19, 1952, the team at the Palomar Observatory was engaged in a routine survey of the star-studded sky. Their mission was to capture multiple photographs of the same celestial region in an attempt to spot and identify asteroids. As the clock struck 8:52 PM, their photographic plate recorded an intriguing sight: a trio of stars exhibiting unusually high magnitude. However, the real mystery unfolded at 9:45 PM when the same part of the sky was photographed again, and the three stars had utterly vanished. This enigma remains unresolved even today.

The Unraveling of an Astronomical Puzzle

Stars, as we know, do not simply vanish into thin air. They might explode or briefly flare up, but they don't disappear without a trace. Yet, the evidence was right there, etched in the photographic plates: the visible three stars in the first image were nowhere to be found in the second. This led to the hypothesis that these stars might have experienced sudden dimming, but substantiating this claim was another challenge in itself.

The two photographic shots showing the three stars (left center image) and the later one in which they vanished. Credit: Palomar/Solano Observatory, et al.

Follow-up Observations: More Questions Than Answers

Subsequent observations revealed no signs of the stars dimming beyond magnitude 24, suggesting a dimming factor of 10,000 or more. This raised an intriguing question: what could possibly cause stars to dim so drastically and rapidly?

One theory posited that it wasn't three stars, but a solitary star. This lone star might have briefly emitted a radio flash, akin to a magnetar, and a stellar-mass black hole passing between the star and us could have caused a gravitational lensing effect, splitting the glow into three separate images.

However, this theory is riddled with inconsistencies, primarily because such an event is extremely rare. Moreover, other photographic records from the 1950s reveal similar rapid disappearances of multiple stars, which would be hard to explain through gravitational lensing alone.

Alternative Theories: From Oort Cloud Objects to Nuclear Tests

Another theory suggests that the three bright spots might not have been stars at all. If they were individual objects, a certain event must have triggered their simultaneous illumination. Given the time interval of approximately 50 minutes, these objects, considering the speed of light, could not be more than 6 AU apart. This led to the speculation that they could be Oort Cloud objects that were briefly illuminated but subsequently drifted along their orbits, hence their disappearance from later observations.

Another idea postulated that these weren't celestial objects at all. Since the Palomar Observatory is in proximity to the New Mexico deserts, where nuclear tests were conducted, radioactive dust from these tests could have contaminated the photographic plates, creating the illusion of bright spots.

The Mystery Continues 

Despite these theories, the truth remains elusive. The real breakthrough would come from capturing similar occurrences in modern sky observations that would enable prompt follow-up investigations. Until then, this celestial whodunit waits to be unraveled.

Sources: Universe Today, ArXiv