In 1952, 3 stars disappeared from the night sky. What happened to them?

On July 19, 1952, the Palomar Observatory near San Diego, California, conducted a survey of the night sky, focusing on a particular area and photographing it several times, in an attempt to detect objects in the solar system such as asteroids as they passed by. In front of the stars, which dims them a little.

At 8:52 that evening, they took an image containing three stars close together. At 9:45 p.m., a second photo of the same area was taken. This time, the objects were nowhere to be seen.

This is somewhat unusual. Stars like Betelgeuse may dim or explode Twilight for hours or daysBut this one was there at 8:52pm and was gone less than an hour later. So what happened to them?

A new team interested in such “transients” has looked into the matter and come up with several possible explanations. First, they looked to see if things had been seen since.

“We took advantage of the capabilities of the virtual observatory to search for the fleeting trio in recent images and catalogs,” the team wrote in their preprint paper, which has not yet been peer-reviewed. “The result of this research concluded that the transit does not appear in any subsequent image of that area during the subsequent 69 years.”

Next, the team compared the transits with other stars captured in the same region. If there are significant differences, especially towards the edges of objects, this may indicate defects in the photographic plates or even elementary particles colliding with the plates. However, they found that the shapes were remarkably similar, despite their different sizes.

“In summary, we find no evidence that the transient is anything other than a real, as-yet-resolved point source of light,” the team wrote. “In particular, the files 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 ruled out that stars dimmed independently, given the rarity of stars that disappear in this way at all. Whatever causes one thing to disappear from our sight is the reason for them all to disappear. The same is true if these are dim objects that cause them to brighten briefly due to a common event.

If the object is really three separate objects in space, that means they would have to be close together for the light to arrive (and hence not) during the time frame of that hour. If this is the correct explanation, it places the objects much closer to our solar system than other explanations do.

“To be causally connected, the three light sources must physically be located within 6 astronomical units of each other and no more than 2 light years apart[s] far. This distance is less than the nearest star, the Alpha Syn system, which makes the location of the three transits close to our sun, if not the inner solar system, or even Earth’s orbit.

This would increase the possibility that the objects are asteroids or Other objects in our solar systemAnd perhaps the Oort Cloud, explaining why it was not seen in later surveys.

Another possibility suggested by the team is that these objects were caused by gravitational lensing, where space-time is distorted by very heavy objects, sometimes magnifying the objects far beyond the distance of astronomers. Although it’s a cool idea, the team said it’s difficult to imagine because it would raise another mystery.

“Models that include optically illuminated background objects for less than 1 hour combined with foreground gravitational lensing appear plausible,” the team wrote. “If so, a large number of massive objects with structures that act as lenses would be needed, producing three images, to interpret the transients under the watch.”

Unfortunately, there is no definitive answer yet, and the team has called for further follow-up searches for similar transients.

The study is published on a preprint server arXiv.