In 2015, the star Tabby, revealed an unusual behavior: it blinked and its brightness faded for a few days and then returned to normal for no apparent reason. This cycle, which was repeated several times at an unpredictable pace, raised several hypotheses.
The star, located 1000 light years from Earth, in the constellation Cygnus, was discovered in 1890. But it had gone unnoticed until astrophysics Tabetha Boyajian, of the Louisiana State University (USA) noticed this anomaly without precedents.
The brightness of the star fell to 22% and sometimes a little less. Meanwhile, another group of scientists later found that the overall brightness of the star was decreasing over time.
The mysterious obscurity of Tabby, also known as KIC 8462852, began to generate an interesting debate among scientists. Among the theories that tried to explain this phenomenon were fragments of planets, swarms of comets or clouds of dust.
But the hypothesis that most caught the attention was the possible existence of an ‘alien mega-structure’ that approaches the star to extract its energy, thus causing the weakening of its brightness.
Now, in a study published this month in the Royal Astronomical Society by researchers at Columbia University it seems to have finally deciphered the mystery of the most mysterious star ever discovered.
The authors suggest that the star caught a natural satellite of some planet that orbits it, as if the Sun captures our Moon to revolve around it. But this was possible after the exoplanet was destroyed. Therefore, the ‘exoluna’ found Tabby as her new ‘father’.
This icy and dusty moon began to receive more radiation than usual due to its proximity to the star. In this way, its outer layers began to melt.
All of these fragments were thrown into space like comets, while the smaller blocks became clouds of dust, and the larger blocks inherited the orbit of the exoluna.
In this way, a ring of particles formed around the star, blocking the light for different periods and intensity.
“The exoluna is like an ice comet that evaporates and throws these rocks into space. Finally, the exoluna will evaporate completely, but it will take millions of years to melt and be consumed by the star,” says Brian Metzger, principal investigator of the study.
It seems that humanity will have to wait a long time to confirm this theory, that if true, it would be one of those cosmic exceptions that occur in the universe, since the simulations of the scientists established that their theory is possible only in one 10% of cases in which an exoplanet is destroyed.