US astronomers and Canada for the first time discovered a two-star system, one of which has just formed a pulsar in 2674 light years from the ground. The neutron star pulls the substance from the neighboring star, which is doomed to turn into a white dwarf. Preliminary results are published in Preprint article available on the ARXIV website.
The unusual source of gamma radiation 4FGL J1120.0-2204 was initially fixed by the Fermi Space Telescope. The researchers assumed that it could be a millisecond pulsar (SME) – a neutron star, which very quickly rotates due to the accretion of the substance from the neighboring star. Most of the famous SMEs in the Galaxy Milky Way passed the step of acceleration and gradually slow the rotation, and their companions are helium white dwarfs, which can no longer transmit their substance to the neutron star.
Fermi’s cosmic telescope discovered many new bright sources of gamma radiation in the Milky Path. The multivol observations identified them as millisecond pulsars whose companions are stars of the main sequence enriched with hydrogen. Such objects are called spiders, as they devour the substance of neighboring stars. In the future, they are divided into two subclasses: “black widows” (the mass of the companion is less than 0.05 mass of the Sun) and “Krasnikinniki”, if a star companion retains more mass.
4FGL J1120.0-2204 was the second brightness of an unidentified source of gamma radiation. Astronomers analyzed the source spectrum using the SOAR telescope (The Southern Astrophysical Research) and found that the object is a double system with a rather hot companion, whose occurs period is 15 hours. The gamma source is likely to be a millisecond pulsar, which is at a distance of 820 parses (2674 light years). The mass of the star-companion is 0.17 masses of the Sun, that is, it is in the intermediate stage of transformation into helium white dwarf.
According to models, two billion years of age, the properties of this unusual system will correspond to those for a typical pulsar-white dwarf system with a short orbital period. Thus, the 4FGL J1120.0-2204 is most likely a “missing link” in the evolution of such double systems.