Atmospheric chemical abundances and the evolutionary status of the spectroscopic and speckle-interferometric binary 9 Cyg

We have performed speckle interferometry with the 6-m telescope of the Special Astrophysical Observatory and spectroscopy (at 3700–9200 Å) with the 2-m telescope at Peak Terskol of the spectroscopic and interferometric binary 9 Cyg, which is a composite-spectrum star with an orbital period of 4.3 yrs. The atmosphere of the system’s primary component is analyzed in detail. The luminosities of both components estimated to be L ₁ = 103.8 L _⊙, L ₂ = 55.2 L _⊙, where L _⊙ is the solar luminosity, and their effective temperatures to be T _e (1) = 5300 K and T _e (2) = 9400 K. The abundances of C, N, O, Fe, and other elements in the primary’s atmosphere have been derived. The chemical composition shows signatures of mixing of material from its atmosphere and the region of nuclear reactions. The evolutionary status of 9 Cyg has been determined. The binary’s age is about 400 million years; the brighter star is already in the transition to becoming a red giant, while the secondary is still in the hydrogen-burning stage near the zero-age main sequence. We suggest an evolutionary model for the binary’s orbit that explains the high eccentricity, e = 0.79.     

Mössbauer characteristics,mineralogy and isotopic age (Rb-Sr,K-Ar) of Upper Riphean glauconites from the UK Formation,the southern Urals

Comprehensive mineralogical analysis, Mössbauer spectroscopy and isotopic-geochronological study have been carried out for globular phyllosilicates (GPS) of glauconite group from the Uk Formation, the second one below the top of the Upper Riphean stratotype in the southern Urals. Glauconites have been sampled in the Kurtaza and Kulmas sections remote from each other in the Alatau anticlinorium that corresponds to western facies zone of the Bashkirian meganticlinorium. As is shown, size and density monomineral fractions of globules are represented by Al-glauconite according to established structural formula. The isotopic (Rb-Sr and K-Ar) dating of glauconites from the Uk Formation is performed for the first time along with computer simulation of cation arrangements in their crystal lattice and comparison of the results obtained with data of Mössbauer spectroscopy. It has been assumed by simulation that origin and transformation of the Rb-Sr and K-Ar systems in glauconite are concurrent to stages in structural evolution of this mineral, which have been controlled by geological and geochemical events in the history of sedimentary successions. The approach has been aimed at recognition of stratigraphically meaningful isotopic dates corresponding to the glauconite formation at the stage of the early diagenesis close to sedimentation time and the “rejuvenated” dates characterizing ages of subsequent geological events. The comparison of simulated cation arrangements with data of Mössbauer spectroscopy shows that the Rb-Sr (663 ± 9 Ma) and K-Ar (669 ± 16 Ma) dates established for glauconites correspond to the time of early diagenesis in their host sediments, being suitable for age assessment of the Uk Formation. The dates obtained are of interregional and wider significance, as they must be taken into consideration when constructing the general curve of Sr isotope variations in the Late Riphean oceans.     

Abnormally high waves due to spectral instability of surface waves

The outcomes of our laboratory experiments corroborate hypotheses advanced earlier, dedicated to the mechanism of origination of abnormally high waves under the development of spectral instability. We have clarified the characteristics of spectral instability development including the dependences of the value of the downshift of the spectral maximum and distances at which it occurs on the steepness of waves and width of the initial spectrum. In addition, we have revealed the dependence of the number of abnormal waves on the fraction of spectral energy transferred to the low-frequency range and on the stage of spectral instability development. Our results offer the basis for creating a statistical model of the origination of abnormally high waves.     

The current systems of the magnetic substorm growth and explosive phases

On the basis of the geomagnetic data of highlatitude arctic stations the development of polar magnetic substorms is examined. It is shown that there exist two current systems of the magnetic substorm: DP₁₁ and DP₁₂. ₁₁ is a current system with one westelectrojet in the nighttime auroral zone. That system is peculiar to the break-up phase of a substorm. DP₁₂ is a two-vortex current system in the polar cap with two auroral electrojets, eastward and westward, of about equal intensity. The DP₁₂ system is typical for growth and recovery phases.There are two different types of substorm development. The first type is characterized by the DP₁₂ system during the growth phase. The intensity of this current system increases until the explosive phase begins. The other type does not seem to be characterized by any distinct current system during the growth phase. The commencement of such a substorm is associated with a rapid explosive development of the DP₁₂ system.A conclusion about the the different origins of the DP₁₁ and DP₁₂ current systems is made.     

Requirements for the appearance and basic design parameters of a micro-rocket system meant for launching nano-, pico,and femtoscale spacecraft

The paper proposes a concept of a microrocket system meant for the injection of nano-, pico-, and femtoscale satellites into near-Earth orbit. Requirements for the appearance and basic design parameters of the micro-rocket system are substantiated. Characteristics of possible prototypes and analogues of this system are analyzed.     

Some features of the evolution of carbonate accumulation in the earth’s history: Communication 1. Evolution of the intensity, mechanism, and setting of carbonate accumulation

Marine and oceanic carbonate accumulation during the Vendian-Cambrian was mostly controlled by the life activity of organisms, which either constructed skeletons and directly transferred carbonates into sediments or created geochemical environments favorable for the precipitation of the carbonate substance. During the first third of the Paleozoic, the chemogenic and biochemogenic mechanisms of limestone formation were replaced by the biogenic one. In the dolomite formation, to the contrary, the chemogenic mechanism progressively replaced the biochemogenic mechanism and its pseudobiogenic modification. The carbonate accumulation occurred in the cyclic mode and its intensity increased with time to reach its peak in the Late Cretaceous. The main paleogeographic domains of carbonate accumulation also experienced changes. They were mainly represented by spacious shelf seas in the Paleozoic; by intraoceanic shoals, reefs and pelagic realm in the Mesozoic; and by the pelagic realm and, to a lesser extent, reefs in the main Cenozoic.     

Solar protons in the Earth’s magnetosphere from riometric and satellite data during magnetic storms in October 2003

The fluxes and penetration boundaries of solar energetic particles on the CORONAS-F satellite during October 2003 superstorms are compared with the riometric absorption measurements on a worldwide network of riometers. The dynamics of the polar cap boundaries is investigated at various phases of magnetic storms. The dependence of absorption on time of the day and on solar proton spectrum is calculated at various phases of a solar energetic particle event.     

Dynamics of the earth radiation belts during strong magnetic storms based on <Emphasis Type="Italic">CORONAS-F</Emphasis> data

The results of an experimental study of the variations in the intensity of the fluxes of the Earth radiation belt (ERB) particles in 0.3–6 and 1–50 MeV energy intervals for electrons and protons, respectively, are reported. ERBs were studied during strong magnetic storms from August 2001 through November 2003. The results of the CORONAS-F mission obtained during the magnetic storms of November 6 (D _st = ?257 nT) and November 24, 2001 (D _st = ?221 nT), October 29–30 (D _st = ?400 nT) and November 20, 2003 (D _st = ?465 nT) are analyzed. The electron flux is found to decrease abruptly in the outer radiation belt during the main phase of the magnetic storms under consideration. During the recovery phase, the outer radiation belt is found to recover much closer to Earth, near the boundary of the penetration of solar electrons during the main phase of the magnetic storm. We associate the decrease in the electron flux with the abrupt decrease of the size of the magnetosphere during the main phase of the storm. Note that, in all cases studied, the Earth radiation belts exhibited rather long (several days) variations. In those cases where solar cosmic-ray fluxes were observed during the storm, protons with energies 1–5 MeV could be trapped to form an additional maximum of protons with such energies at L >2.     

Sr chemostratigraphy of carbonate sedimentary cover of the Tuva-Mongolian microcontinent

This study uses Sr isotope chemostratigraphy to place constraints on the depositional age of carbonate rocks from the Tuva-Mongolian microcontinent. The age of carbonate rocks of the Irkut Formation (⁸⁷Sr/⁸⁶Sr initial ratio equal to 0.70480–0.70485) is determined to be older than 1250 Ma, whereas carbonates of the Zabit (0.70706–0.70727 and 0.70828–0.70848) and Agarin Gol (0.70725–0.70743) formations were deposited in the interval 630–560 Ma.