Research Institute Crimean Astrophysical Observatory

Crimea, Russia

Research Institute Crimean Astrophysical Observatory

Crimea, Russia
Time filter
Source Type

Messina S.,INAFCatania Astrophysical Observatory | Muro Serrano M.,Zeta UMa Observatory | Artemenko S.,Research Institute Crimean Astrophysical Observatory | Bailey J.I.,University of Michigan | And 2 more authors.
Astrophysics and Space Science | Year: 2015

We measure the photometric rotation periods of the components of multiple systems in young stellar associations to investigate the causes of the observed rotation period dispersion. We present the case of the wide binary AG Tri in the 23-Myr young β$\beta$ Pictoris Association consisting of K4 + M1 dwarfs. Our multi-band, multi-season photometric monitoring allowed us to measure the rotation periods of both components PA=12.4d$P_{\mathrm{A}} = 12.4~\mbox{d}$ and PB=4.66d$P_{\mathrm{B}} = 4.66~\mbox{d}$, to detect a prominent magnetic activity in the photosphere, likely responsible for the measured radial velocity variations, and for the first time, a flare event on the M1 component AG Tri B. We investigate either the possibility that the faster rotating component may have suffered an enhanced primordial disc dispersal, starting its PMS spin-up earlier than the slower rotating component, or the possibility that the formation of a debris disc may have prevented AG Tri A from gaining part of the angular momentum from the accreting disc. © 2015, Springer Science+Business Media Dordrecht.

Babin A.N.,Research Institute Crimean Astrophysical Observatory | Koval' A.N.,Research Institute Crimean Astrophysical Observatory
Kinematics and Physics of Celestial Bodies | Year: 2010

This paper investigates the velocity field in the flare region during the impulsive phase of the 2B/M2. 3 importance solar flare of June 26, 1999. Spectral Hα observations of the flare with high temporal and spatial resolution were made with the KG-2 coronograph of the Crimean Astrophysical Observatory. Velocities are estimated by the bisector method. The velocity field in the flare region and flare kernel during the impulsive phase are found to be very complex, have a fine structure, and alter rapidly with time. Different elements of the flare exhibit line shifts of different magnitude and even different directions. This means that there are local Doppler motions in the fine structural elements of the flare. © 2010 Allerton Press, Inc.

Zyelyk Y.I.,Ukrainian Academy of Sciences | Stepanyan N.N.,Research Institute Crimean Astrophysical Observatory | Andryeyeva O.A.,Research Institute Crimean Astrophysical Observatory
Journal of Automation and Information Sciences | Year: 2010

On the basis of observation data of magnetic fields on the Sun on 26-year time interval in the result of correlation and spectral analysis of time series, which were formed in separated latitudinal zones, we estimate latitudinal drift of disbalance flow of magnetic field on the whole and differential rotation and latitudinal drift of components of disbalance flow with definite significant periods of rotation. We form the picture of evolution of disbalance flow of magnetic fields, information about which may be used on creation of magnetohydrodynamic models of global flows of the Sun and for their verification. © 2010 by Begell House Inc.

Yurovskiy Yu.F.,Research Institute Crimean Astrophysical Observatory
CriMiCo 2014 - 2014 24th International Crimean Conference Microwave and Telecommunication Technology, Conference Proceedings | Year: 2014

Disturbance, caused by a solar flare, is accompanied with the radio emission of falling down frequency, affects the biosphere and influences on operation quality of many devices of surface and space equipment. The presence of heterogeneity on the way of radio waves results in the origin of interference and scintillation of observed radio emission. Comparison of analytical description of scintillation with the results of spectral observations from remote points showed that the formation of fiber-structures with intermediate speed of drift and the wide-band pulsations of solar flare radio emission is satisfactorily explained by multibeam propagation of radio waves through coronal plasma. © 2014 CriMiCo'2014 Organizing Committee, CrSTC.

Tsap Y.T.,Research Institute Crimean Astrophysical Observatory | Isaeva E.A.,Research Institute Crimean Astrophysical Observatory
Cosmic Research | Year: 2013

On the basis of data, obtained by means of the ground-based solar service RSTN (Radio Solar Telescope Network) and the geostationary satellite system GOES, the relationship between the solar cosmic rays (SCR) intensity Ip with the proton energy Ep & 1 MeV and parameters of meter-decameter type II radio bursts in the frequency range of 25-180 MHz is studied. The process of proton acceleration by shock waves was characterized by the frequency drift velocity of radio bursts VmII and the relative difference between radio emission frequencies at the first two harmonics b. It is shown that the coefficient of correlation between Ip and b increases with Ep growing from 0. 40 to 0. 70, while a similar coefficient between Ip and VmII does not exceed 0. 30. Indications in favor of the two-stage SCR acceleration model are obtained. © 2013 Pleiades Publishing, Ltd.

Loading Research Institute Crimean Astrophysical Observatory collaborators
Loading Research Institute Crimean Astrophysical Observatory collaborators