Unusual rotation modes of minor planetary satellites

An analysis of the character of the possible dynamics of all hitherto known planetary satellites shows two satellites—Amalthea (J5) and Prometheus (S16)—to have the most unusual structure of the phase space of possible rotational motion. These are the only satellites whose phase space of planar rotation may host synchronous resonances of three different kinds: the α resonance, the β resonance, and a mode corresponding to the period doubling bifurcation of the α resonance. We analyze the stability of these states against the tilt of the rotational axis.     

Generalized Laplace coefficients and Newcomb derivatives

It is shown how the generalized Laplace coefficients can be employed to deduce explicit formulas for ordinary and Newcomb derivatives of the Laplace coefficients.      

Some characteristics of astronomical climate on Mount Koshka,Simeiz

Coefficients of atmospheric extinction in the Johnson-Cousins system are determined for the astronomical point at Mount Koshka (Simeiz, Crimea). The astronomical point is characterized by high transparency and frequent periods of low quality of the image, which is explained by its position between the Crimean Range and the Black Sea.     

Physical conditions in the plasma tail of comet C/1987 P1 bradfield

Photometric measurements of photographic images of comet C/1987 P1 Bradfield have been carried out with a flat-bed scanner equipped with a slide module. Lengthwise and transverse photometric profiles of the cometary plasma tail have been obtained. Magnetic field induction and some other physical characteristics of the cometary plasma tail observed in November 1987 have been estimated with the use of the diffusion model for a cometary tail by Shul’man and Nazarchuk (1968). It has been shown that the scanned images of comets can be used for estimating the physical characteristics of cometary tails.     

New type of extragalactic objects?

We have reported the discovery of a population of the normal extragalactic field galaxies with the clear presence of strong FHIL (forbidden high by ionized lines) and HeII 4686 emission. In this paper we present a dozen of them extracted from the SDSS dr7. The high resolution spectra 0.86 ? /px obtained with the 6-m telescope of the Special Astrophysical observatory of Russia are introduced for one of them, SDSS J093801.63 + 135317.0 confirming the presence of strong and wide FHIL and HeII 4686 emission. These objects show typical narrow (FWHM ~ 120 - 250 km s^-1) emission lines both of HI and forbidden emission lines of [NII] 6548/84, [SII] 6717/31, [OI] 6300, [OII] 3727, and [OIII] 5007/4959 with underlying stellar absorption lines, coupled with the strong FHIL emission of [FeVII] 5721, 6087, [FeX] 6375, [FeXI] 7892, [FeXIV] 5303, and HeII 4686, sometimes very broad up to 1500 km s^-1. Following the direct images, all morphological types are introduced, spherical, elliptical, spiral, barred spiral, etc., without morphological or other peculiarity and any signs of "standard" AGN activity. None of them are X-ray source. The appearance of the FHIL emission in normal galaxies (the objects of SBN/HII/ELG spectral types) might be one of the important sign of the beginning of the AGN activity. The existence of the numerous normal extragalactic objects with FHIL and HeII 4686 emission tell us that the link between the AGNs and the normal galaxies perhaps might be realized with the FHIL flare in normal galaxies. For all of them, the existence of the nonthermal source in normal galaxies should be proposed.