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Scientific achievements, Galaxy sector

As a result of use of the CCD system and the achromatic analyzer, developed and manufactured in the SAO, the following results were made on the Main Stellar Spectrograph of the BTA telescope:

• for the first time a magnetic field was registered on normal white dwarfs. In 40 Eri B a magnetic field was discovered that varies with the rotation period of 10.2 minutes, and with an amplitude of 3.5kG. In comparison with the known magnetic white dwarfs, this object has a 30 times weaker magnetic field;
• it was found that the main sequence star HD37776 has a uniquely strong magnetic field of about 70kG of a complex multipole structure.

A study of variability of the first galactic superluminal radio source GRO J1915 +10 with the RATAN-600 showed a delay of flare activity at 3 frequencies of 5-10 days after the X-ray flares with an inversion of the radio spectrum. The spectrum of the second superluminal galactic radio source GRS J1655-40 remained optically thin and nonthermal during the outbreak, and its radio emission decayed exponentially. For the first time an extended nonthermal radio envelope was found around this source, which could be formed either as a result of a recent (less than 500 years ago) supernova explosion, or as a result of blowing the jets of relativistic electrons from the central source.

According to a survey of galactic neutral hydrogen at the RATAN-600, linear dimensions, density and mass of the HI for more than 5000 gas clouds in the third quadrant of galactic longitudes were obtained. The distribution of linear dimensions of clouds in the first approximation is power-law. The distribution of clouds by concentrations depends on the galactic latitude. The distribution of cloud mass suggests that the merger, rather than fragmentation dominates in collisions. In the regions of low and high mass the distribution has droops, apparently associated with the evaporation of clouds of small mass under the action of very hot fractions of interstellar gas on one side, and with the gravitational instability on the other side. The data obtained allow us to make reliable conclusions about the nature of various physical processes in the interstellar medium.

Speckle interferometric observations with the diffraction spatial resolution of 0.02 arcsec at the 6-m telescope for the first time revealed asymmetry of the visible disk of the long-period variable star R Cas, and made direct estimates of a young binary system DF Tau, located in a complex of star formation.

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