Researchers make new efforts to unveil the mystery of disappearing stars from the 1950s

The universe is full of surprises. Every time humans make the mistake of considering themselves all-knowing, the universe humbles them. Something like this happened one night in 1952 when right in front of the astronomers, three stars vanished. This has long been an intriguing mystery for researchers all across the world. After years of research, scientists have finally made progress on what might have happened to them, per IFL Science.

The 1952 survey of the night sky undertaken by the Palomar Observatory, has been haunting astronomers for decades. The objective of the survey was to record asteroids passing in front of the stars. It was found that stars dim whenever such bodies pass near them, the survey was done to monitor such changes. However, the outcome flipped everything on its head. Rather than getting information about the impact of asteroids, the researchers ended up with vanishing stars. The picture captured on July 19 at 8:52 pm in the observation showed three stars close to each other, they were nowhere to be seen at the snip taken at 9:45 pm. The scientists called these bodies, "transients."

Researchers at the Centre for Astrobiology (CAB) in Madrid decided to take up this incident and look deeply into it. Their first course of action was to see whether the transients ever reappeared again in the sky. "We took advantage of the Virtual Observatory capabilities to look for the triple transient in more recent images and catalogs," wrote the team in their pre-print paper. "The result of this search concluded that the transient does not appear in any later image of that region during the subsequent 69 years."

Thereafter they began comparing the size and shape of the transients with stars in the same area. Though the sizes were different, the stars and transient were found to be of similar shape. This removed the doubt that there was any flaw on the photographic plate, or that any elementary particle hit the plates which captured the transients. "In summary, we find no evidence that the transient is anything other than a bona fide unresolved, point source of light," the team wrote. "In particular, the profiles show no evidence of a moving source such as an aircraft, asteroid, or elementary particle nor of a defect in the photographic plate."

The team does not believe that the transients dimmed independently. Since something like this was not recorded anywhere else. If stars had the capability of dimming in such a manner, this phenomenon would have been recorded more actively in other zones of the sky, but that was not the case. The conclusion was that all three bodies disappeared because of the same reason. The assertion is that the transients were so close to each other that light (or lack of it) impacted all three of them within that hour's time frame. This implies that these objects are much closer to the solar system than previously assumed by the scientists.

"To be causally connected, the three light sources must reside physically within 6 au of each other and are no more than 2 light-years [s] away. This distance is less than the nearest star, the alpha Cen system, bringing the venue of the three transients to a distance within our Sun’s vicinity, if not the inner Solar System, or even Earth’s orbit," the team shared. Hence, these transients might have been asteroids or other objects in our solar system, perhaps the Oort cloud, because they were not visible in the following surveys.

The other possibility was that the objects appeared in the sky because of gravitational lensing. As per Hubble, this phenomenon occurs when a huge amount of matter, like a cluster of galaxies, creates a gravitational field that distorts and magnifies the light from distant galaxies. The effect is similar to looking through a magnifying glass. The team was not exactly sold on this idea.

"Models involving background objects that are optically luminous for less than one hour coupled with foreground gravitational lensing seem plausible," the team wrote. "If so, a significant population of massive objects with structure serving as the lenses, to produce three images, are required to explain the sub-hour transients." Therefore, despite the researchers seeming to have made progress in their efforts to unravel the mystery the truth still remains shrouded.