V.4 No 1

55

On orbital stability of oscillators

To understand utterly the conditions at which the galactic dynamic fields form, we have to note that just as in stars, stellar matter within the galactic nucleus is also inhomogeneous and unstable. The first cause of such instability can be the bursts of nova and supernova during the formation of galaxy, which transfer the substance by many thousand parsecs. Even when the consequences of burst have been smoothed for the star, the displacement of rotation centre, which arose because of the burst, remains with all consequences for the galaxy, and during its evolution it stabilises due to the rotation and inertial mass of galaxy. Another cause of instability can be the instability of galactic nucleus, because of its too fast rotation. With it, double and more galactic nuclei can form, and this will also have effect on the structure of dynamic galactic field. As the result, stellar systems of galaxy nucleus move in closed trajectories, and this is one of main premises, why the dynamic galactic field arises. To illustrate the said, see in Fig. 13 the photo and map of the central region of our Galaxy, in which the trajectories of stellar motion in the region are shown. We see the complicated and asymmetric as to each other system of central stars of different size and energy. It is understandable that such system can give some resulting instability. And presence of two arms in our Galaxy evidences two centres of charges in the nucleus.

a

b

Fig. 13. "This is the image of the very inner region of Milky Way (a), several light years across, having been got in the middle of 2002 with NACO instrument at the 8.2-m VLT YEPUN telescope. Compact objects are stars, their colours indicate their temperature (blue = "hot", red = "cool"). There is also the diffusive infrared radiation from interstellar dust between the stars. Two yellow arrows denote the location of black hole SgrA* in the very centre of Milky Way. The scale is given. One light year relates to the angle of 8 arcsec in the sky. Credit: ESO" [12].

"SgrA* and S2 are identified in the left part of image (b). In the right part the orbit of S2 is shown in the observation between 1992 and 2002, relatively the object SgrA* (denoted by the circle). Locations of S2 at different epochs are denoted by cross with dates (expressed in the parts of a year) shown at each point. The size of cross denotes the measurement error. The elliptic curve is the most probable orbit of S2 around SgrA*. Credit: ESO " [12]