Astronomers may have discovered exoplanets outside the Milky Way
The universe is vast, and a man with his weak tools is trying to find in the darkness at least the objects closest to him. First - the planets of the solar system, then - alien stars, then - the planets of these stars in our galaxy. Having gained some experience in terms of detecting exoplanets, astronomers decided to try to do the same with another galaxy. Scientists, as far as one can judge, managed to detect several exoplanets at a distance of 3.8 billion light years from the Sun.
Using data from NASA's space observatory, astronomer Xinyu Dai, an astrophysicist and professor at the University of Oklahoma, discovered with his team several planets outside the Milky Way. According to him, the sizes of these planets are different - some not larger than our moon, others - about the same as Jupiter.
Astronomers use several methods for detecting distant planets from us. Since they are too far from the Earth to use conventional optical telescopes, other methods come into play. According to project participants, Einstein's theory of relativity helped them.
One of the provisions of this theory is that light can be deflected due to strong gravitational influence. We are talking about gravitational lensing, an effect the possibility of using which for one reason or another was predicted by Einstein himself. So, the lens that allowed Earth scientists to observe distant objects - this is just a galaxy located 3.8 billion light-years from Earth. Until now, the effect of gravitational microlensing has been used only to search for planets that revolve around the stars of the Milky Way.
The mass of the galaxy, which is located far from us, is so great that the light passing by it changes the direction of "movement" and some characteristics. By the way, with the help of the lensing effect, scientists back in 1991 managed to detect a quasar located 6 billion light-years from Earth, as well as measure its characteristics. This quasar is a very bright object with a supermassive black hole RX J1131−1231 in the center.
So, the light that comes to us from the above quasar comes to us through the galaxy, which serves as a kind of gravitational lens. Studying the radiation characteristics of a quasar that passed through the lens, experts realized that the detected energy shifts are explained by the presence of exoplanets between the Earth and the quasar.
In a university press release, study participants set out in ever less formal language, stating that the process of detecting remote exoplanets is "a very cool science . " The photo, which was obtained by scientists, in their opinion will allow the development of planetology further. The photo shows the central elliptical object - this is a galaxy in which stars with exoplanets around are located. The white dots at the top and the white mark at the bottom are the radiation coming from the black hole.
According to scientists, distant galaxies contain trillions of exoplanets, many of which can be inhabited or potentially inhabited. Some colleagues of the authors of the study expressed their support. But few show enthusiasm. A large number of experts believe that the study is quite interesting, but the data obtained by astronomers can be interpreted in different ways. For example, detected objects may belong to our galaxy.
By the way, not so long ago, NASA agency toldon the results of cooperation with the telecommunications giant Google. The partner provided the agency with machine learning technologies that automatically process a huge amount of data sent to the Earth by the Kepler telescope. This method has given astronomers a lot, and one of the results is the discovery of the eighth exoplanet in the Kepler-90 system .
All planets in this system are found by transit photometry. This method makes it possible to detect an exoplanet when it passes through the disk of its star. At this time, the luminosity of the star for some time decreases and astronomers fix the planet (well, or another object).