Algorithms for searching and identifying components of originally binary stars, tidal destroyed by SMBH

Рассматривается генетическая связь сверхскоростных (СЗ) и центральных (S) звезд в окрестности сверхмассивной черной дыры (СМЧД). Находясь на расстояниях порядка радиуса Галактики, в прошлом они могли быть компонентами двойной звезды, которая испытала приливное воздействие со стороны СМЧД. Предлагается апробирование двухэтапного алгоритма поиска генетически связанных в прошлом СЗ-S-пар, используя данные каталогов [1,2]: 1) реконструкция методом обратного интегрирования «возвращенной» траектории СЗ; 2) анализ компланарности орбиты СЗ, «возвращенной» в окрестность СМЧД, и орбиты наблюдаемой S-звезды. Эта задача дает независимый тест нашему знанию о распределении барионного и темного вещества, а также построенному на их основе гравитационному потенциалу Галактики, что имеет важное космологическое и эволюционное значение.The genetic relationship of hypervelocity (HVS) and central (S) stars in the vicinity of a supermassive black hole (SMBH) is considered. Being at distances of the order of the Galaxy radius, in the past they could have been a binary star that experienced the tidal impact of the SMBH. It is proposed to test a two-stage algorithm for searching for genetically related in past HVS-S-pairs using catalogs [1, 2]: 1) reconstruction by the method of reverse integration of “returned” trajectory of the HVS; 2) Analysis of the coplanarity of the orbits of HVS, “returned” in SMBH-neighborhood, and the observed S-star. This task provides an independent test of our knowledge of baryonic and dark matter distribution, as well as the gravitational potential of the Galaxy based on them, which has important cosmological and evolutionary significance

The role of Rossiter—McLaughlin effect in study of Close Binaries

Большинство звезд для нас являются точечными источниками излучения. Это ставит проблему исследования звездных поверхностей, что подталкивает к развитию методов доплеровского картирования, поляриметрии, томографии, интерферометрии. Для их тестирования подходят только самые близкие звезды, тогда как затменные переменные звезды весьма благоприятны для достижения высокого пространственного разрешения при условии, что их орбита лежит на луче зрения. Фотометрический и спектроскопический анализ затмений позволяет определить геометрические и физические параметры звезд, а также наклоны звездных экваторов компонентов к плоскости орбиты. Оценку наклонения дает измерение эффекта Росситера Маклафлина, о котором рассказывается в лекции.Most of the stars are point sources for us. This raises the problem of studying stellar surfaces, which pushes us to ward the development of Doppler mapping, polarimetry, tomography, optical and infrared interferometry. To test these methods, only nearby stars are suitable, while eclipsing binaries are useful to obtain high spatial resolution. Photometric and spectroscopic analysis of eclipses allows determining geometric and physical parameters of stars, as well as inclinations of stellar equators to orbital plane. Estimations of inclinations can be obtained from the measurement of Rossiter—McLaughlin effect, which will be discussed in the lecture

Binary coalescence from case A evolution -- mergers and blue stragglers

We constructed some main-sequence mergers from case A binary evolution and studied their characteristics via Eggleton's stellar evolution code. Both total mass and orbital angular momentum are conservative in our binary evolutions. Some mergers might be on the left of the ZAMS as defined by normal surface composition on a CMD because of enhanced surface helium content. The study also shows that central hydrogen content of the mergers is independent of mass. As a consequence, we fit the formula of magnitude and B-V of the mergers when they return back to thermal equilibrium with maximum error 0.29 and 0.037, respectively. Employing the consequences above, we performed Monte Carlo simulations to examine our models in NGC 2682 and NGC 2660. In NGC 2682, binary mergers from our models cover the region with high luminosity, but its importance is much less than that of AML. Our results are well-matched to the observations of NGC2660 if there is about 0.5Mo of mass loss in the merger process.Comment: 14 pages, 12 figures. accepted by MNRA

On the Scenario of the Moon Formation

Рассматривается задача гравитационного захвата околосолнечной Луны как возможный вариант образования спутника Земли. В модели трех тел (Солнце, Земля, Луна) производится отбор кривых сближений Луны и Земли, допускающих пересечение сферы Хилла Земли. Такие варианты повторяются в модели N-тел для оценки влияния приливных сил на перекачку орбитального момента Луны (P M orb) относительно Земли в ее собственный (P M s ∼ 10−6P M orb), что не приводит к захвату в короткой шкале времени ∼ 100 лет. Как показывает моделирование, захват Луны за одно сближение реализуется при учете небольшого (≈ 0.05 % от орбитальной скорости Луны) ее «притормаживания» за счет, например, столкновения с астероидом.The problem of gravitational capture of the Moon as near-sun planet is considered as a possible variant of the formation of the Earth satellite. In the model of three bodies (Sun, Earth, Moon), the Moon and Earth approaching trajectories are selected, allowing the intersection of the Earth’s Hill sphere. Such variants are repeated in the N-body model to assess the effect of tidal forces on the transfer of the orbital moment of the Moon (P M orb) relative to the Earth into its own (P M s ∼ 10−6P M orb), which does not lead to capture in a short timescale ∼ 100 years. It was shown that the capture of the Moon in one approach is realized if one takes into account a small (≈ 0.05 % of the orbital velocity of the Moon) “braking” due, for example, to a collision with an asteroid

Interstellar Planets and Comets: Origin Mechanisms, Discovery Ways, and Statistics

We consider mechanisms of origin and detection of interstellar planets and comets.Рассмотрены механизмы образования и обнаружения межзвездных планет и комет

Extremely Wide “Binary Stars”

В кратком обзоре ставится проблема эволюционной связи центральных околоядерных S-звезд и сверхскоростных звезд (СЗ), которые в недалеком прошлом были компонентами общей родительской двойной звезды, до ее захвата в галактический центр, населенный сверхмассивной черной дырой (СМЧД). Представляет интерес взаимной «реконструкции» популяций S-звезд и СЗ, рассчитанных в рамках классического сценария Хиллза, по принципу дополнения их наблюдательных данных. Обсуждается возможность «восстановления» из наблюдений S-СЗ-пар в Галактике.In a brief review, the problem of the evolutionary relationship between central near-nuclear S-stars and hypervelocity stars (HVS), which in the recent past were components of a parent binary star, before its capture into the galactic center inhabited by a supermassive black hole (SMBH), is posed. Of interest is the mutual ”reconstruction” of populations of S stars and HVS calculated within the framework of the classic Hills scenario, based on the principle of supplementing their observational data. The possibility of ”recovery” from observations of S-HVS-pairs in the Galaxy is discussed

Interstellar planets

Лекция посвящена изучению роли гравитационного рассеяния в эволюции планетных систем. В рамках этого механизма объясняется происхождение облака Оорта и свободных от родительской звезды астероидов, комет и планет (АКП).The lecture is devoted to the study of the role of gravitational scattering in the evolution of planetary systems. This mechanism explains the origin of the Oort cloud and free asteroids, comets, and planets (ACPs) from the parent star

STATISTICAL RESEARCH IN EVOLUTIONARY GENETIC RELATIONSHIP OF DMS-, DW-, KW- AND KE-TYPES OF DOUBLE STARS

Statistical relations as spectrum-period, mass of primary component-semi-major axes of an orbit, excesses of luminosity and radius-mass of component, Karetnikov's diagram, modern and initial distributions of the binaries in the 1 ps3 of Sun neighbourhood allow to solve the problem of evolutionary relationship for close binary systems and describe conditions at which evolutionary transitions such as DMS -> DW -> KW <- KE take place

Tidal torque constants as a critical test for an evolution of close eclipsing binaries

Individual tidal torque λ 2,E 2 and apsidal-motion k 2 constants were calculated for 112 close eclipsing binaries (CEBs) with Detached components belonging to the Main Sequence (DMS-type) from the catalogue by Svechnikov and Perevozkina (Catalogue of orbital elements, masses and luminosities of variable stars of DMS-type and some results of its statistical treatment, Ural State University Press, Yekaterinburg, pp. 1-5, 1999) and for 95 detached binaries taken from the catalogue by Torres et al. (Astron. Astrophys. Rev. 18:67, 2010) on the base of theoretical evolutionary stellar models including tidal torque constants by Claret (Astron. Astrophys. 424:919, 2004). A method of the inversion of model track grid into isochrones was formulated as a complex interpolation procedure for DMS-binaries data. Sets of isochrones were computed in k 2-M, k 2-R, λ 2-M, λ 2-R, E 2-M, and E 2-R planes. Calculated tidal torque constants allow to test stellar structure theory by comparing observed and estimated values of apsidal motion period and analyzing the correlation between timescales of synchronization, circularization, magnetic braking, as well as nuclear burning of DMS-components. © 2011 Springer Science+Business Media B.V

BLUE STRAGGLERS AS A MERGING PRODUCT OF LOW-MASSIVE MAIN SEQUENCE BINARIES WITH DETACHED COMPONENTS

In the framework of magnetic braking formalism the evolutionary chain describing the sequential evolutionary transitions of the low-massive detached close binaries into "short- periodic" RS CVn-type systems and then into W UMa-class contact stars with the final stage of the single objects of Blue Stragglers-type was reconstructed. This problem was solved with the use of extensive observation materials. The relations of statistics and lifetimes obtained for systems participating in evolutionary chain serve as an evidence for genetic relationship of given objects