On July 19, 1952, Palomar Observatory conducted a photographic survey of the night sky, capturing multiple images of the same sky region to aid in asteroid identification and other astronomical studies.
During this survey, at approximately 8:52 pm, a photographic plate recorded the presence of three clustered stars emitting light. With a magnitude of 15, these stars were relatively bright in the image.
However, when the same sky region was photographed again at 9:45 pm, the three stars had mysteriously vanished without a trace. In less than an hour, they had completely disappeared.
It is highly unusual for stars to vanish. Although they can explode or experience temporary brightness fluctuations, complete disappearance is unprecedented. Yet, the photographic evidence is undeniable. The first image clearly shows the presence of the three stars, while the second image reveals their absence.
Initially, it was speculated that the stars had suddenly dimmed. However, subsequent observations failed to detect any stars dimmer than magnitude 24. This indicates that the dimming would have been by at least a factor of 10,000.
So, what could possibly cause such a rapid and drastic dimming of stars?
One hypothesis suggests that the three stars may, in fact, be a single star. It is possible that this star experienced a short-lived period of intense brightness, possibly due to a fast radio burst from a magnetar. During this period, it is theorized that a stellar-mass black hole passed between the star and Earth, causing gravitational lensing. This lensing could have resulted in the star appearing as three distinct images for a brief period of time.
However, this explanation raises questions about the rarity of such an event. Other photographic images taken during the 1950s also exhibit rapid disappearances of multiple stars. In some cases, these stars are widely separated, suggesting that gravitational lensing would be insufficient to explain the phenomenon.
Another possibility is that the objects observed were not stars at all. The three bright points are located within a distance of 10 arcseconds from each other. If these were indeed individual objects, their simultaneous brightening must have been triggered by some external factor. Given the timespan of approximately 50 minutes, and considering causality and the speed of light, it can be inferred that the objects were no more than 6 astronomical units (AU) apart. This implies that they would have had to be within a maximum distance of 2 light-years.
An intriguing supposition is that these objects could have been Oort Cloud objects, experiencing a synchronized brightening due to a common event. The subsequent inability to locate them in later observations could be attributed to their drift along their respective orbits.
A third possibility is that the observed objects were not celestial bodies at all. Palomar Observatory is located in close proximity to the New Mexico deserts where nuclear weapons testing took place. It is conceivable that radioactive dust from these tests contaminated the photographic plates, creating bright spots in some images while leaving others unaffected.
Considering the similar disappearances recorded on other photographic plates from the 1950s, this explanation appears quite plausible.
Currently, certainty eludes us. What we truly need is to capture similar events in modern sky surveys, allowing for prompt follow-up observations. For now, this remains a perplexing mystery awaiting resolution.
This article was originally published by Universe Today. Read the original article.
