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We have carried out three-dimensional hydrodynamical modeling of the formation of planets through the merging of a binary system comprised of low-mass (～0.5–1 M⊙) stars in the stage of contracting towards the main sequence. Under certain conditions, the disruption of the more massive component results in the formation of an expanding disk and extended arm. The fragmentation of this arm leads to the formation of planetary-mass clouds (<5 M J where M J is the mass of Jupiter), whose orbits can have semimajor axes of 0.4 to 5 AU and substantial (～0.5) eccentricities. 相似文献
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We have carried out three-dimensional hydrodynamical modeling of the process of circularization in close binary systems with fully convective components that are close to filling their Roche lobes. The computations are based on the smooth-particle (SPH) method and were carried out for the case of eccentricities less than 0.1 on the dynamical time scale. We find that the circularization time in such systems should be of the order of hundreds of orbital periods. 相似文献
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N. M. Sushchevskaya E. A. Korago B. V. Belyatsky A. N. Sirotkin 《Geochemistry International》2009,47(10):966-978
Petrological and geochemical data obtained on Neogene magmatism restricted to a deep fault in Andree Land at Spitsbergen Island,
which was related to the overall restyling of the Arctic territory at 25–20 Ma, indicate that the derivation of the Neogene
magmas was significantly affected by the continental pyroxenite mantle. The Neogene basalts are noted for a radiogenic isotopic
composition of Pb (207Pb/204Pb= 15.5–15.55, 206Pb/204Pb = 18.4–18.6, 208Pb/204 Pb = 38.4–38.6) and Sr(87Sr/86Sr = 0.7038–0.7048) at low 143Nd/144Nd = 0.5129. Melts of this type are the extremely enriched end member of the isotopic mixing of a depleted and enriched sources
and determine a geochemical trend that passes through the compositions of alkaline magmas from Quaternary volcanoes at Spitsbergen
and weakly enriched tholeiites of the Knipovich Ridge, which started to develop simultaneously with the onset of Neogene magmatism
in the western part of Spitsbergen. The composition of the liquidus olivine (which is rich in NiO) indicates that melting
occurred in the olivine-free mantle. Our data thus testify that a significant role in the genesis of the Neogene magmas was
played by continental pyroxenite mantle. 相似文献
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We consider mass exchange in close binaries containing low-mass, fully convective components on the dynamical time scale. We present the results of three-dimensional hydrodynamical simulations of this process in close binaries contracting onto the main sequence (binary pre-MS stars). Our results suggest that some systems with superplanets could be formed by this process, which could be considered a special type of binary star. We have determined the ranges of the relative donor masses that allow the merger of the binary components and the formation of systems with superplanets or the survival of the binary during the mass exchange. These process should result in a deficit of binaries with similar component masses. 相似文献
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Demidov N. E. Borisik A. L. Verkulich S. R. Wetterich S. Gunar A. Yu. Demidov V. E. Zheltenkova N. V. Koshurnikov A. V. Mikhailova V. M. Nikulina A. L. Novikov A. L. Savatyugin L. M. Sirotkin A. N. Terekhov A. V. Ugrumov Yu. V. Schirrmeister L. 《Izvestiya Atmospheric and Oceanic Physics》2020,56(11):1376-1400
Izvestiya, Atmospheric and Oceanic Physics - This work summarizes the archived data of geocryological and hydrogeological conditions in the west of Nordenskiold Land on the Spitsbergen Archipelago.... 相似文献
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F. V. Sirotkin 《Solar System Research》2007,41(2):132-139
A scenario is considered for the formation of a planetary system through the merging of a binary star comprised of low-mass (0.5–1 M ⊙) stars in the stage of contracting towards the main sequence. According to our previous computations (Sirotkin and Karetnikov, 2006), under certain conditions, the destruction of the more massive component can result in the formation of a central star, an accretion disk, and an extended arm. The extended arm is fragmented to form clouds of planetary masses (<5M J). The formed disk and clouds rotate in the same direction as the central star. The clouds are in elongated orbits (e > 0.3) lying in the orbital plane of the initial binary system. To test these earlier results, we repeated computations for the same system parameters but with higher accuracy. The new computations confirmed the earlier results and gave new information about the cloud and disk structure. 相似文献