Found a second star near which builders of the Dyson sphere can live
In mid-October 2015, astronomers from Yale University spoke about unusual fluctuations in the brightness of the star KIC 8462852 in the constellation Cygnus, the luminosity of which has halved by almost a quarter in the last 7 years. These "blinks" for the first time pointed to the possibility of the presence in its vicinity of the so-called Dyson sphere, a trap for the energy of a star created by an over-developed civilization of aliens.
Initially, scientists assumed that such a “blinking” of a star could be caused by a swarm of comets that closed its light from observers on Earth, but in January 2016, American astronomer Bradley Schaefer discovered that the brightness of KIC 8462852 inexplicably fell by 0.16 magnitude over the last century that cast doubt on this theory. Subsequently, scientists working with the Kepler telescope confirmed that the brightness of this luminary really falls.
A team of German astronomers led by Simone Scaringi of the Institute for Extraterrestrial Physics in Garching, Germany, discovered another similar star, EPIC 204278916, and found a potential explanation for its unusual nature by observing the night sky of the southern hemisphere of the Earth with an ALMA microwave radio telescope.
This star is located in the constellation Scorpio, at a distance of about 400 light-years of Earth, inside the so-called OB-association of Scorpio-Centaurus. It is a group of about a thousand relatively young and hot stars born inside the giant "star nurseries" about 5-11 million years ago.
EPIC 204278916 is one of the youngest stars in this "family" whose birth has not yet ended. Its mass at the moment is approximately two times smaller than the Sun, and its brightness is approximately equal to how much light and other forms of electromagnetic radiation our body produces.
According to Skaringi and his colleagues, they discovered unusual fluctuations in the brightness of this luminary quite by accident, studying the photographs and data that the Kepler telescope collected in August-November 2014 as part of the K2 mission after its “resurrection”.
In these images, scientists discovered gigantic fluctuations in the brightness of the new “alien star, ” during which the strength of its luminescence in one case decreased by several hours by 65% over 79 days of observation. In addition, Scaringi and his colleagues found other, less lasting and strong decreases in brightness, and the frequency of occurrence of many of these “eclipses” coincided with the speed of rotation of the star.
Interested in this unusual phenomenon, scientists began observing EPIC 204278916 with the ALMA telescope, suspecting that such drops in brightness could cause, as the discoverers of the original "alien star" suggested, swarms of comets or debris from a destroyed planet. In favor of this, the fact that EPIC 204278916 is a fairly young star, the processes of planet formation around which has not yet been completed.
In fact, as these observations showed, the potential source of shading the light of a young star may not be Dyson’s man-made sphere, but a protoplanetary disk that surrounds it like a kind of “donut”. We see this donut from the end, thanks to which it remains invisible to infrared telescopes, capable of capturing the thermal radiation generated as a result of friction of dust particles and gas molecules inside this disk.
The gas and dust in this disk are distributed extremely unevenly, and therefore the brightness of the light of the star “flashing” it on the way to Earth will vary greatly depending on the density of the part of the “donut” that is now looking at us. This may explain why the brightness of EPIC 204278916 changes in an incomprehensible way for us, and why the time of occurrence of these decreases is synchronized with the rotation of the star around its axis.
All this, as Scaringi emphasizes, does not explain why the brightness drops in the original “alien star”. KIC 8462852, unlike EPIC 204278916, is not a young star and its spectrum does not indicate the presence of a protoplanetary disk or any large accumulations of dust and gas in its vicinity. Apparently, in its fading involved some other mechanism that scientists have not yet disclosed.Do you like the article?
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