For the first time in the history of astronomy, scientists have
observed planets “living” outside the Milky Way. The discovery is
reported by a scientific article that Xinyu Dai and Eduardo Guerras of
the University of Oklahoma published in The Astrophysical Journal
Letters.
Scientists were interested in the unusual behavior of the elliptical
galaxy RXJ 1131-1231. It is a gravitational lens for four distant
quasars that illuminate it. However, one of the spectral lines of iron
in the x-ray emission of these quasars, adopted by the orbiting
observatory Chandra, showed strange shifts in energy.
The researchers suggested that this phenomenon is caused by the
gravitation of some objects located in the lens galaxy. Having
calculated on a supercomputer, they came to the conclusion that only
planets can provide such a picture.
The authors estimated the total mass of these worlds. There were
incredibly many of them: in the galaxy, for one star of the main
sequence, there must be two thousand objects with masses lying in the
range from the mass of the moon to the mass of Jupiter.
“We are very pleased with this discovery, for the first time someone discovered planets outside our galaxy,” Dai admits.
Note that the method of gravitational lensing is the only one of many
ways that allows to open exoplanets, observing them at such a
respectful distance already at the existing level of technology. True,
it was previously used to detect other worlds exclusively in our galaxy.
Now for the first time with his help it was possible to open the
“signatures” of exoplanets outside the Milky Way.
“This galaxy is located at a distance of 3.8 billion light years from
us, and there is not the slightest chance of seeing these planets
directly, even with the best telescope imaginable in the science fiction
scenario,” explains Gerras. In the same study, it was possible not only
to confirm the existence of planets, but also to estimate their mass.
