Possible scenarios for the formation of Ap/Bp stars     

A. V. Tutukov  A. V. Fedorova 《Astronomy Reports》2010,54(2):156-162

Possible paths for the formation of Ap/Bp stars—massive main-sequence stars with strong magnetic fields—are analyzed based on modern theories for the evolution of single and binary stars. Assuming that the strong magnetic fields of these stars are the main reason for their comparatively slow axial rotation and the observed anomalies in the chemical compositions of their atmospheres, possible origins for these high magnetic fields are considered. Analysis of several possible scenarios for the formation of these stars leads to the conclusion that their surface magnetic fields are probably generated in the convective envelopes of the precursor stars. These precursors may be young, single stars with masses 1.5–3 M _⊙ that formed at the peripheries of forming star clusters and ended their accretion at the Hayashi boundary, or alternatively close binaries whose components have convective envelopes, whose merger leads to the formation of an Ap/Bp star. Arguments are presented supporting the view that the merger of close binaries is the main channel for the formation of Ap/Bp stars, and a detailed analysis of this scenario is presented. The initial major axes of the merging binary systems must be in the range 6–12 R _⊙, and the masses of their components in the range 0.7–1.5 M _⊙. When the merging components possess developed convective envelopes and fairly strong initial magnetic fields, these can generate powerful magnetic fields “inherited” by the products of the merger—Ap/Bp stars. The reason the components of the close binaries merge is a loss of angular momentum via the magnetic stellar winds of the components.  相似文献   

New in the physics of planetary atmosphere     

O. I. Korablev  L. V. Zasova  A. A. Fedorova  A. V. Rodin  N. I. Ignatiev  T. K. Breus  M. N. Izakov  B. S. Maiorov  A. A. Krivolutsky  E. V. Petrova  A. Yu. Ivanov  A. Yu. Trokhimovskii 《Izvestiya Atmospheric and Oceanic Physics》2009,45(4):503-516

We present here an overview of the results of Russian investigations of planetary atmospheres in 2003–2006 prepared by the Commission on Planetary Atmospheres of the National Geophysical Committee for the National Report on Meteorology and Atmospheric Sciences to the 24th General Assembly of the International Union of Geodesy and Geophysics (Perugia, June 2–13, 2007).  相似文献   

Distribution and Composition of Anapa Bay-Bar Sediments     

Kosyan  R. D.  Kosyan  A. R.  Krylenko  V. V.  Fedorova  E. A. 《Oceanology》2020,60(2):267-278

Oceanology - Abstract—The paper describes the composition of bottom and beach sediments of the large accumulation form (the Anapa bay-bar). It has been shown that the sand particles size...  相似文献