A few years ago, a star was discovered that was cataloged as the most mysterious in the universe. Called KIC 8462852 or Star of Tabby (in honor of the astronomer Tabetha Boyajian, who led the team that began to study this star in depth), this star is bigger than our sun and has a peculiar way of shining.
Among the most controversial explanations that were offered, they found that the star had an ” alien mega-structure ” surrounding it. Although a study published in ArXiv.org broke with the mystery and explained that it was only a ring of dust, and not a giant object between the star and us.
Now the Tabby star has once again shown a strange characteristic. According to the observation blog led by Dr. Boyajian, the mysterious star has been attenuated by at least 5% (perhaps up to 10%) breaking the record for the largest drop since the data compiled by Kepler in 2011.
“Today we have very big news: the data taken in TFN last night show that the flow dropped by 5%,” Boyajian wrote. “This fall has now been confirmed by AAVSO observer John Hall, it seems we have broken the record set last week in the deepest fall observed since Kepler.”
We still do not know what this means, but the data will help build a better profile of the distant star of 1,280 light-years to help discover why it fades the way it does.
The main objective of Kepler is to look for attenuated stars, since this is how we find exoplanets. When a planet passes between a star and the Earth as it rotates, it will attenuate the star by a small amount, 1%, at regular intervals. But Tabby does not follow this pattern. Its darkening is very irregular, occurs at unpredictable intervals, and to varying degrees. In Kepler’s observations of 2011, it decreased by up to 22%. It had several important attenuation events throughout 2017, in May, June, August, September, October and November / December.
No hypothesis seems to explain all the rarity
On the other hand, data files recently revealed that, in addition to attenuation, the star has also gone through periods of significant brightness in the past. And part of what is so disconcerting about KIC 8462852 is that no hypothesis seems to explain all the rarity.
Although the idea of an “alien mega-structure” was the one that most captivated the public, it was discarded by scientists when it was discovered that some wavelengths of light were blocked more than others. If a structure were there, it would block all wavelengths.
Other less exotic theories include a ringed planet passing in front of the star, either absolutely huge or a smaller one with an orbital wobble; a swarm of comets; space junk; the star swallowing a planet; or something happening inside the star itself. But the most likely explanation is an uneven cloud of dust rotating around the star, since that would block ultraviolet light more than infrared light. Anyway, it would have to be a lot of dust and be very scattered to block so much percentage of the star because, as a comparison, the giant Jupiter only blocks 2% of the light of our Sun (a smaller star than Tabby).
Two other stars with similar peculiar light fluctuations have been observed. The white dwarf WD 1145 + 017 has drops of up to 30% in its stellar flow, possibly indicating a dust disk. And it has been observed that the variable star RZ Piscium, which emits large amounts of infrared radiation, darkens erratically up to 10%. Probably the dust is also the culprit.
The mysteries are always present in science (especially in space), although often it is only a matter of time to solve them. Recently some students, with the help of a satellite, solved a mystery that was more than 60 years old.