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“Invisible” stars discovered at a distance of 2500 light years from Earth

In space, an extremely unfriendly environment forman, something happens all the time. Various celestial objects, including stars, galaxies, clouds of dust and gas are constantly changing. It is for this reason that the European Space Agency has developed the Gaia Space Telescope, which studies the sky again and again. Such a repeated viewing of the same areas is necessary in order to fix the positions of the stars - Gaia is able to detect thousands of temporary objects (objects that either appear or disappear). Thanks to this, researchers can aim ground-based and space telescopes at the desired part of the sky and study in detail celestial objects, which can turn out to be such phenomena as supernova explosions and other stellar flares.

It turned out that some space objects are able to bend space-time around themselves

Very strange star

In the summer of 2016, astronomers saw a star,which is located at a distance of 2500 light-years from Earth in the constellation Cygnus, as if preparing to become a supernova. However, the next day, the star regained its usual state and a supernova explosion did not occur. But a few weeks later, the situation repeated again: the brightness of the star suddenly increased, and then faded. This cycle was repeated five times in 500 days. But what was it and how is this possible? The results of a study of this mysterious star are published in the journal Astronomy & Astrophysics.

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In an official press release published onThe website of the European Space Agency, one of the co-authors of the work, Lukasz Wyrzykowski from Warsaw University (Poland), said that such behavior is uncharacteristic of stars, since no type of supernova or other star shows such behavior. In subsequent observations, the researchers used data obtained using more than 50 telescopes from around the world. And each time they saw the same picture: a star called Gaia16aye really behaved strangely.

Gaia Space Telescope time and time again looking at the same parts of space

Researchers believe that the reason for suchunusual behavior lies in the fact that the gravity of an invisible object that deformed the fabric of space-time, increased the light of the star when it passed nearby. Later, astronomers discovered that this invisible object is a double star located 2.544 light years from Earth, which is so dim that we cannot see it. She seems invisible to us. However, based on how a star’s gravity affects the amount of light emitted, astronomers were able to calculate the mass, distance, and orbit of a pair of red dwarf stars.

How gravity changes spacetime

The abnormal brightness of the star suggested the presence ofa double object that produces the so-called gravitational microlenses - the effect predicted by Einstein, which occurs when the gravity of the object in the foreground causes space-time to double, increasing the objects behind it, like a cosmic magnifying glass. These lenses enhanced the light of the star every time it passed behind them, and the stars themselves were virtually invisible from Earth. Scientists used the phenomenon of gravitational microlenses to carefully observe some of the oldest stars, galaxies and objects in the Universe, but the effect can also reveal the properties of objects much closer to us and rare cosmic phenomena. Researchers believe that many mysterious objects, such as black holes, can be detected in the future.