Astronomers have been able to trace the last dimming of the mysterious "alien star KIC 8462852 and measure its spectrum, the analysis of which, as its discoverer Tabetha Boyadjian hopes, will help us understand who is involved in its" blinking "- comets, asteroids, planets or ultra-developed aliens.
Illustration by RIA Novosti. Alina Polyanina
“We spent almost four years without sleep or rest, awaiting another tarnishing of KIC 8462852. We were assisted by astronomers from all over the world working with the largest telescopes in the world. Before this event, we were not sure that this tarnishing was not a single event, and only now these fears have been dispelled, says Tabetha Boyajian from Yale University (USA).
The Riddle of the Swan
In mid-October 2015, and Boyagian, her colleagues spoke about unusual fluctuations in the brightness of the star KIC 8462852 in the constellation Cygnus, which may indicate the presence in its vicinity of the so-called Dyson sphere, created by a super-developed alien civilization.
Initially, scientists assumed that such a "blinking" of the star could be caused by a swarm of comets that blocked its light from observers on Earth, but in January 2016, the American astronomer Bradley Schaefer discovered that the brightness of KIC 8462852 inexplicably dropped by 0.16 magnitudes over the last century, which called into question this theory.
Initially, a number of skeptics tried to deny the very fact of the tarnishing of KIC 8462852 in the short and long term, but later scientists working with the Kepler telescope, as well as Russian astronomers from the Pulkovo Observatory, confirmed that the brightness of this luminary was declining in the past. Last week, the brightness of KIC 8462852 began to fall again, having dropped by 2% in a few hours.
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According to Boyagian, the first dimming of the "alien stars" were discovered virtually by accident, and therefore astronomers were not ready to observe them and reveal the reasons for what caused KIC 8462852 to drastically decrease brightness. This time, thanks to a specially organized Kickstarter campaign and the help of scientists from all the leading ground and space observatories in the world, the tarnishing of the Tabby Star has been comprehensively studied.
Giant shadow
The dimming of KIC 8462852 in May this year, according to the astronomer, is not accidental and speaks in favor of the fact that these "blinks" are caused by some object in the orbit of the "alien star", making one revolution around the star in about 750-780 days. This is supported by the fact that other drops in brightness, which were recorded by the Kepler telescope during the first phase of its work, occurred with approximately the same frequency, and the brightness of the star during them changed in exactly the same way.
This is how the artist imagined a swarm of comets near the star KIC 8462852 / ASA / JPL-Caltech
Accordingly, this significantly reduces the likelihood that its light is obscured by some periodic object inside the solar system or a star or some other celestial body located on the path between the Sun and KIC 8462852. Now scientists are monitoring the dimming of neighboring stars in order to exclude this possibility.
An interesting coincidence, according to Boyagian, is that the hypothetical planet of this star, on which a year would last 750-780 days, then it would be almost in the center of the "zone of life." This, as the astronomer emphasizes, is nothing more than an accident and does not mean that there is a Dyson sphere or some other man-made structure in the orbit of this planet.
On the other hand, a similar frequency of "blinking" KIC 8462852 suggests that it should be obscured by a giant object about five Jupiters in size. As David Kipping, a renowned planetary scientist at Columbia University, explained, such a celestial body cannot be a planet - red dwarfs and other small stars have approximately the same dimensions.
Its tracks would have been visible to the Spitzer orbiting infrared telescope, but Boyagian and her colleagues did not record them for about a year of observations. Moreover, these observations rule out the possibility of a large number of asteroids and comets at such a distance from the star. All this once again made this star, as Boyajian notes, even more mysterious than we previously thought.
“We made observations in different parts of the spectrum, many of which were not available to Kepler during the first decreases in the star's brightness. Comparing them with each other, we hope to understand what this object consists of, how “transparent” it is and how it came into being. It is important that we conducted and are conducting observations in real time, which cannot be done with Kepler, the astronomer continues.
Rings and retinue of "Saturn"
The answer to this riddle, according to Fernando Ballesteros from the University of Valencia (Spain) and his colleagues, may not be hiding in the planet or its potential debris, but in another type of objects that we are familiar with - giant gas and dust rings in giant planets …
They drew attention to the fact that the dimming of KIC 8462852 did not occur randomly, but proceeded in a kind of "triplets" - at first the brightness of the star dropped relatively weakly for short periods of time, then it dimmed strongly, and then dimmed weakly again. All of this reminded them of what the sun would look like if we were looking at it from a position located beyond the orbit of Saturn, the main "Lord of the rings" in the solar system.
If KIC 8462852 has such a planet, then its rings can reflect a large amount of its light if they are rotated at an angle in relation to observers in orbit or on the surface of the Earth. In this case, the passage of such a “Saturn” across the disk of KIC 8462852 or behind it will noticeably reduce the brightness of the star.
Small drops in the brightness of the "alien stars", in turn, will be caused by the so-called Trojan asteroids, thousands of which orbit the giant planets at a fixed distance behind and in front of them.
Despite the elegance of this theory, not all astronomers agree with it. For example, planetary scientist Jason Wright from the University of Pennsylvania (USA) notes that both the “swarm” of Trojans and the planet's rings must be gigantic. The width of the latter, according to his calculations, should be comparable to the distance between the Sun and the Earth to reflect a sufficient amount of light from KIC 8462852, and the total mass of the asteroids should be equal to or greater than the mass of Jupiter.
Kipping adheres to a similar position - he noted that such a "planet" will not be inferior in size to large brown dwarfs and therefore it will be visible in the infrared part of the spectrum. Therefore, this theory can hardly explain the mysterious dimming of the alien stars.
Other mysteries of KIC 8462852, such as its gradual tarnishing, remain a mystery to astronomers. As Boyyajian notes, today there is no doubt that they exist, but the new data not only does not explain them, but makes them more incomprehensible and confusing. She hopes further observations will help us uncover the secrets of the most mysterious star in our Galaxy.