A group of researchers compared data from 70 years ago to data from today. They found over 800 stars vanished mysteriously.
History would have us believe that the night sky is permanent and unchanging. After all, for centuries, navigators have used fixed stellar patterns to guide their ships. And our eyes continue to draw the exact outlines of the same heroes and villains that astronomers have identified for millennia. But what if we haven’t been paying attention? What if our night sky is changing, and some stars suddenly wink out of visibility?
A group of researchers from the Vanishing and Appearing Sources during a Century of Observations (VASCO) project want to know all kinds of vanishing objects in the night sky and what could be causing their disappearance.
Even though our current understanding suggests that stars change slowly, and that mysterious disappearances should leave traces, this does not mean that all stars shine continuously. In fact, variable stars that pulsate and change in brightness, fill the sky.
VASCO is looking for anything that goes from being a perfectly stable star to utterly disappearing. Researchers haven’t seen this before, and it’s the kind of discovery that could lead to new physics.
Modern automated telescopes can catalog the entire sky at a rate that previous generations of astronomers could only imagine.
You Might Like This: Could F-Type Stars Allow Life To Form?
The VASCO team is comparing data from 70 years ago to today’s data to determine how the sky has evolved. The team’s hunt for high-quality historical data led them to use both old and modern telescopes to conduct a survey. So far, the survey has yielded more than 800 missing stars. Scientists will need to process and analyze in-depth many of them. While there is no perfect match for a vanishing long-lived, stable star, most of the candidates discovered are intriguing in their own right.
They discovered several transients that appear on one image and then vanish. These account for the majority of what they’ve found so far. But there are a few more things they’re not sure about.
So they looked at some of these short-lived transients, and they don’t appear to be M-dwarf flares (massive outbursts caused by tangled magnetic fields of dim red dwarf stars that can cause them to brighten by a factor of 100 or more) or supernovae.
Other less likely candidates include variable stars and catastrophic variables or novae. Novae are eruptions on the surface of white dwarf stars in binary systems.
None of the sources are close to a known variable. Also, the companion star in a nova system should be faintly visible even if the white dwarf isn’t.
Scientists said several of these objects flared up to at least eight to nine magnitudes, or several thousand times brighter in a relatively short time, but fade in just a few minutes.
Of course, with 800 candidates, there’s still a lot of work to be done. And to be clear, it’s probably certainly a mixed bag of different types of items.
What could be the probable explanation if those 800 candidates turn out to include an ideal disappearing star?
One explanation could probably be a failed supernova that occurs when a massive star collapses into a black hole. Thus consuming the rest of the star from the inside out without causing a visible explosion. Also, no extra-terrestrial activity is involved in a failed supernova. However, this explanation has a lot of odds against it.
Other natural processes that would result in a star simply disappearing are difficult to imagine at the moment. Speculating on hypothetical novel physics that might be involved in this cosmic vanishing act is pointless unless a candidate appears with features that can be investigated.
However, this presents another possibility that has sparked VASCO’s imagination since the beginning: the prospect that seemingly impossible astronomical phenomena could reveal the existence of advanced alien civilizations.
An increase in telescope size and sensitivity, along with computing power, has brought astronomy into the “big data” era.
Nevertheless, many SETI scientists have argued that they are more likely to detect the presence of aliens through otherwise mysterious behaviors of stars and other objects than they are by radio signals intentionally or accidentally beamed in our direction by alien life.
According to the hypothesis, if civilizations grow far enough, at least some of them would obtain the technology needed for stellar engineering. That would modify the appearance of stars in previously unexplainable ways. The Dyson sphere, a halo of orbiting power plants that would be the most effective way of harvesting energy from a star, is a classic illustration of this.
The VASCO team hints at exciting findings that have already surfaced from the data and are awaiting formal publication. Meanwhile, the VASCO project continues. Many of the candidates discovered so far are still awaiting analysis and confirmation. So far, scientists have examined only about a fourth of the sky.
Hopefully, more volunteer citizen scientists and new automation approaches being developed in partnership with the Spanish Virtual Observatory will speed up progress.
The researchers are now looking into the idea of putting together a citizen science project supported by artificial intelligence. This would aid in the discovery of new aspects of our night sky.