Astronomers have noticed some oddities in the data collected by the Gaia space telescope during the period from July-August 2016. One of the stars showed a very strange behavior – it faded and disappeared from the field of view of the telescope. A few weeks later, she appeared, gradually regained normal brightness and again began to fade to complete disappearance. Further study of this phenomenon showed that this star itself does nothing of the kind, and the observed effects are created by variable distortions of the space-time continuum created by the gravity of a massive invisible object located between the “strange” star and the Earth.
Currently, astronomers have already figured out what this invisible object is. This is the binary star system 2MASS19400112 + 3007533, located at a distance of 2544 light years from us. It consists of two dwarf red stars, whose mass is 57 and 36 percent of the mass of the Sun. They revolve around the general center of mass of the system with a period of 2.88 Earth years and glow so dimly that they cannot be seen even with the most highly sensitive astronomical instruments. Only the effect of micro-gravity lens created by the stars allowed astronomers to calculate the distance to the system, its composition, mass and orbits of the stars included in it.
Because the spinning stars of the 2MASS19400112 + 3007533 system create a “moving” gravitational lens called Gaia16aye, the light from the stars in the background is equally unstable. “Not only did the light from a distant star change abruptly, but not smoothly, in 500 days of observation, we saw five cases of the complete disappearance and reappearance of this star,” says Lukash Vyrzykowski, an astronomer from Warsaw University.
Now, astronomers are going to find several more such micro-gravitational lenses formed by invisible objects, similar to the binary system 2MASS19400112 + 3007533. In the future, these microlenses can be used to search for lonely black holes, the mass of which is comparable to the mass of individual stars. This search is included in the main tasks of the Gaia telescope, and the study of such black holes, which are known to date only a few pieces, can tell scientists a lot about the formation of these objects, and about their role, which they play in the development of the galaxy in which they are located.
“Our new method allows us to see cosmic objects and phenomena invisible under ordinary conditions,” says Lukash Vyrzykovsky, “I am very optimistic about this and I believe that we will be able to find many small black holes this year.”