Author name code: kostik ADS astronomy entries on 2022-09-14 author:"Kostik, Roman I." OR author:"Kostyk, Roman I." ------------------------------------------------------------------------ Title: Results of observations of wave motions in the Solar facula Authors: Shchukina, N. G.; Kostyk, R. I. Bibcode: 2022KFNT...38...71S Altcode: No abstract at ADS Title: Solar Faculae: Microturbulence as an Indicator of Inclined Magnetic Fields Authors: Stodilka, M. I.; Kostyk, R. I. Bibcode: 2020KPCB...36..153S Altcode: The observations of the solar facula in the Ba II λ 455.403 Å line are used to construct a 3D model of the facula area by solving the inverse nonequilibrium radiative transfer problem and to investigate the fine structure of the field of unresolved velocities (microturbulence). New turbulent structures are formed in the layers of the upper photosphere. They are localized mainly between upward and downward flows with the formation of ring-shaped structures of increased turbulence around these flows. The mechanism of magnetic anisotropy of microturbulent velocity is proposed (small-scale eddy-type plasma motions mainly occur in the planes perpendicular to the magnetic field), which explains the height dependence of the field of unresolved velocities. Anisotropy of microturbulence begins to manifest itself in the lower photospheric layers outside the upward and downward flows, while it manifests itself in the higher layers inside these flows. The increase of microturbulence in the layers of the upper photosphere and the lower chromosphere in the areas between matter flows indicates the presence of inclined magnetic fields, which, along with the blurring of its spatial structure, indicates the existence of a magnetic canopy region. Microturbulence can be used as an additional tool for diagnostics of inclined magnetic fields. Title: Solar faculae: microturbulence as an indicator of inclined magnetic fields Authors: Stodilka, M. I.; Kostyk, R. I. Bibcode: 2020KFNT...36d...3S Altcode: No abstract at ADS Title: Velocity Field Diagnostics of the Quiet Sun Using the Lambda-Meter Method: Si I 1082.7 nm Line Authors: Shchukina, N. G.; Kostyk, R. I. Bibcode: 2020KPCB...36....1S Altcode: The validity of the lambda-meter method for determining the quiet Sun velocity field using the Si I 1082.7 nm line is investigated. To this end, the intensity profiles of this line were calculated for the solar disk center by means of NLTE simulations in a three-dimensional model atmosphere describing the small-scale magnetic activity in the quiet solar photosphere. The velocity field recovered using the lambda-meter method from theoretical NLTE profiles of the Si I 1082.7 nm line was compared with the velocity field from the model atmosphere. The influence of atmospheric and instrumental effects on the results is considered. These effects are atmospheric turbulence and light diffraction by telescope aperture, such as VTT, GREGOR, and EST/DKIST. It is shown that, in the case of observations of the Si I 1082.7 nm line on large-diameter telescopes like GREGOR and EST/DKIST with a spatial resolution substantially better than 0.27″, the lambda-meter method provides reliable values of the velocity field for the lower and upper solar photosphere. For the middle photosphere, the correlation between the inferred and the real velocities is worse, particularly when using the smaller diameter telescopes like VTT. Under a poor spatial resolution exceeding 2″, information about the velocity field can be obtained only for the uppermost photospheric layers. For this case, the lambda-meter velocities turn out to be noticeably smaller than the real values. Title: Long-term monitoring of spectral line variations with the 11-year cycle. Quiet Sun. Authors: Osipov, S. N.; Shchukina, N. G.; Kostyk, R. I.; Stodilka, M. I. Bibcode: 2020A&AT...31..465O Altcode: The monitoring program of long-term variation of selected solar spectral lines is described. The aim of the program is to study how the physical parameters of the quiet solar atmosphere change over the last solar cycle 24. The research is based on high spectral resolution observations of the quiet Sun using the Ernest Gurtovenko horizontal solar telescope of the Main Astronomical Observatory of the National Academy of Sciences of Ukraine. Since 2012 the observations are performed daily, when the weather conditions allow. We found that the line core depths and full widths at half maximum of the Fe I solar spectral lines correlate with the cycle modulation of the total unsigned magnetic field and the Wolf numbers of the Sun. The behaviour of these line parameters can be explained by variations of the temperature of the quiet photosphere during the 11-year cycle. Title: Diagnostics of the velocity field of the quiet Sun using the lambda-meter method: The Si I 1082.7 nm line Authors: Shchukina, N. G.; Kostyk, R. I. Bibcode: 2020KFNT...36a...3S Altcode: 2020KFNT...36....3S No abstract at ADS Title: Features of Convection in the Atmospheric Layers of the Solar Facula Authors: Stodilka, M. I.; Prysiazhnyi, A. I.; Kostyk, R. I. Bibcode: 2019KPCB...35..261S Altcode: According to the data of complex 2D observations on the VTT telescope of the solar facula, a 3D model of the solar atmosphere in the facular region was obtained by solving the inverse radiative transfer problem in the Ba II 4554 A line. The magnetic field was estimated using the Stokes V profiles of the Fe I 15648 A line. The influence of magnetic field on photospheric convection was investigated: spatial variations in temperature and velocities at different heights were considered. It is shown that the mutual transformation of the mechanical and thermal energy of the solar plasma into magnetic energy occurs in the layers of the middle photosphere. The integral effect of a small-scale magnetic dynamo leads to lowering the temperature and slowing down the motion of the predominant downward flows in the layers of the middle photosphere in the facular regions with a strong field (greater than 1 kG), while there is an increase in temperature and acceleration of the motion of the predominant upward flows in the layers of the middle photosphere in the facular regions with a weak field (less than 1 kG). It is shown that the magnetic field of the facula stabilizes photospheric convection, and the small-scale magnetic dynamo causes a double temperature inversion in the photospheric layers of the facula. Title: Features of convection in the atmosphere layers of the solar facula Authors: Stodilka, M. I.; Prysiazhnyi, A. I.; Kostyk, R. I. Bibcode: 2019KFNT...35f..18S Altcode: No abstract at ADS Title: Effect of wave motions in the active region of the solar surface on convection Authors: Kostik, R. I. Bibcode: 2018KFNT...34b..46K Altcode: No abstract at ADS Title: Effect of Wave Motions in the Active Region of the Solar Surface on Convection Authors: Kostyk, R. I. Bibcode: 2018KPCB...34...82K Altcode: The results of the observations of the active region (facula) near the center of the solar disk obtained with the German Vacuum Tower Telescope (VTT; Tenerife, Spain), are discussed. We have determined that the decrease in the contrast (brightness) of the facula with the magnetic field increasing from 130 to 160 mT is due to the fact that the V_V phase shift of waves in this range of magnetic field densities is close to zero (Φ VV ≍ 0), i.e., the wave becomes stationary and does not transfer energy from the photosphere to the chromosphere. The sound waves that propagate from the chromosphere towards the photosphere significantly affect the temperature characteristics of turbulent vortices at the level of formation of the continuous spectrum. In particular, the contrast of granules under the influence of these waves can increase by 25%. Title: Kyiv monitoring program of spectral line variations with the 11-year cycle Authors: Shchukina, Nataliia; Osipov, Sergej; Kostyk, Roman; Stodilka, Myroslav Bibcode: 2018IAUS..340...31S Altcode: Kyiv program of monitoring of long-term variation of solar spectral lines at the horizontal solar telescope of the Main Astronomical Observatory of Ukraine is described. The aim of the program is to clarify the issue how the physical parameters of the quiet solar atmosphere change over the 11-year cycle of solar activity. The diagnostics of the atmospheric variation includes analysis of more than 40 spectral lines of neutral and ionized chemical elements observed at the solar disk and at the limb near north and south poles with high spectral resolution. The results of monitoring show that during 2012-2017 a line core depths and a line full widths at half maximum respond to the cycle modulation of the global unsigned magnetic field of the Sun. Such a correlation can be explained by assuming that temperature gradient of the solar photosphere is growing with solar activity. Title: Kyiv monitoring program of fraunhofer lines variation with 11-year cycle of solar activity Authors: Osipov, Sergii; Kostik, Roman; Shchukina, Nataliia Bibcode: 2017JPhSt..21.1901O Altcode: The monitoring program of long-term variation of selected Fraunhofer lines is described. The aim of the program is to study how the physical parameters of the quiet solar atmosphere change over the solar cycle No. 24. The research is based on high spectral resolution observations of the quiet Sun using the horizontal solar telescope ATSU-5 of the Main Astronomical Observatory of the National Academy of Sciences of Ukraine. The diagnostics of the solar cycle atmospheric variation includes observations of the H alpha, Ca II K&H and about 40 spectral lines of neutral and ionized chemical elements at different positions on the solar disk. Since 2012 the observations are performed daily, when the weather conditions allow. The observational season lasts from March to October. The first results of the observations show that the line core depths and full widths at half maximum of the weak Fe I 538.634 nm, moderate Fe I 539.829 nm, and strong Fe I 558.677 nm lines, as well as the bisector curvature of the last two lines show response to the cycle modulation of the total unsigned magnetic field of the Sun. The behavior of these line parameters can be explained by variations of the temperature and convective motions of the quiet photosphere during this cycle. Title: Monitoring program of selected Fraunhofer lines over the 11-year cycle of solar activity Authors: Osipov, S.; Kostik, R.; Shchukina, N. Bibcode: 2017psio.confE.109O Altcode: No abstract at ADS Title: Two Spectra of Turbulence of the Sun Authors: Kostik, R.; Kozak, L.; Cheremnykh, O. Bibcode: 2017psio.confE.108K Altcode: No abstract at ADS Title: The possible origin of facular brightness in the solar atmosphere Authors: Kostik, R.; Khomenko, E. Bibcode: 2016A&A...589A...6K Altcode: 2016arXiv160203369K This paper studies the dependence of the Ca II H line core brightness on the strength and inclination of the photospheric magnetic field, and on the parameters of convective and wave motions in a facular region at the center of the solar disc. We use three simultaneous data sets that were obtained at the German Vacuum Tower Telescope (Observatorio del Teide, Tenerife): (1) spectra of Ba II 4554 Å line, registered with the instrument TESOS to measure the variations of intensity and velocity through the photosphere up to the temperature minimum; (2) spectropolarimetric data in Fe I 1.56 μm lines (registered with the instrument TIP II) to measure photospheric magnetic fields; (3) filtergrams in Ca II H that give information about brightness fluctuations in the chromosphere. The results show that the Ca II H brightness in the facula strongly depends on the power of waves with periods in the 5-min range, which propagate upwards, and also on the phase shift between velocity oscillations at the bottom photosphere and around the temperature minimum height that is measured from Ba II line. The Ca II H brightness is maximum at locations where the phase shift between temperature and velocity oscillations lies within 0°-100°. There is an indirect influence of convective motions on the Ca II H brightness. The higher the amplitude of convective velocities is and the greater the height is where they change their direction of motion, the brighter the facula. In summary, our results lead to conclusions that facular regions appear bright not only because of the Wilson depression in magnetic structures, but also owing to real heating. Title: What mechanisms allow 5-minute oscillations in active regions of the solar surface to penetrate from the photosphere into the chromosphere? Authors: Kostyk, R. I. Bibcode: 2015KPCB...31..188K Altcode: No abstract at ADS Title: Periodic variations of the H α profile width in the chromosphere of coronal holes as a possible indicator of Alfvén waves Authors: Zubkova, A. V.; Kobanov, N. I.; Sklyar, A. A.; Kostyk, R. I.; Shchukina, N. G. Bibcode: 2014AstL...40..222Z Altcode: We analyze the oscillations of the H α profile width based on our observations of the chromosphere at the base of solar coronal holes. The maximum oscillation amplitude averaged over ten time series is 64 m 0 A. Direct calculations show that this value cannot be reached through temperature oscillations, because the periodic intensity fluctuations observed during our experiment did not exceed 5%, corresponding to H α profile broadening only by 1.5-2 m Å. We hypothesize that the observed variations can result from the propagation of torsional Alfvén waves in the chromosphere of coronal holes. Title: Influence of magnetic field on propagation of five-minute oscillations in the sun's atmosphere: Phase shifts Authors: Kostik, R. I.; Shchukina, N. G.; Kobanov, N. I.; Pulyaev, V. A. Bibcode: 2014KPCB...30...40K Altcode: No abstract at ADS Title: Properties of oscillatory motions in a facular region Authors: Kostik, R.; Khomenko, E. Bibcode: 2013A&A...559A.107K Altcode: 2013arXiv1310.0184K
Aims: We study the properties of waves in a facular region of moderate strength in the photosphere and chromosphere. Our aim is to statistically analyse the wave periods, power, and phase relations as a function of the magnetic field strength and inclination.
Methods: Our work is based on observations obtained at the German Vacuum Tower Telescope (Observatorio del Teide, Tenerife) using two different instruments: the Triple Etalon SOlar Spectrometer (TESOS) in the Ba ii 4554 Å line to measure velocity and intensity variations through the photosphere and, simultaneously, the Tenerife Infrared Polarimeter (TIP-II), in the Fe i 1.56 μm lines to measure the Stokes parameters and magnetic field strength in the lower photosphere. Additionally, we use the simultaneous broad-band filtergrams in the Ca ii H line to obtain information about intensity oscillations in the chromosphere.
Results: We find several clear trends in the oscillation behaviour: (i) the period of oscillation increases by 15-20% with the magnetic field increasing from 500 to 1500 G. (ii) The temperature-velocity phase shifts show a strikingly different distribution in the facular region compared to the quiet region, a significant number of cases in the range from - 180° to 180° is detected in the facula. (iii) The most powerful chromospheric Ca ii H intensity oscillations are observed at locations with strong magnetic fields (1.3-1.5 kG) inclined by 10-12 degrees, as a result of upward propagating waves with rather low phase speeds, and temperature-velocity phase shifts between 0° and 90°. (iv) The power of the photospheric velocity oscillations from the Ba ii line increases linearly with decreasing magnetic field inclination, reaching its maximum at strong field locations. Title: Two spectra of turbulence of the sun Authors: Kozak, L. V.; Kostyk, R. I.; Cheremnykh, O. K. Bibcode: 2013KPCB...29...66K Altcode: No abstract at ADS Title: What are solar faculae? Authors: Kostyk, R. I. Bibcode: 2013KPCB...29...32K Altcode: No abstract at ADS Title: Different Modes of Turbulence in the Active Regions of the Solar Photosphere Authors: Kozak, L. V.; Kostik, R. I.; Cheremnykh, O. K. Bibcode: 2013OAP....26..271K Altcode: In work the range of different methods for the analysis of characteristics of turbulent processes in the active regions of the solar photosphere has been used. The changes of fluctuations distribution function and its moments were analyzed, spectral analysis was carried out.It was found out from the observations of active region carried out with the 70-cm vacuum tower telescope VTT in Isanie (Tenerife Island, Spain) that the turbulent processes in the sun photosphere are characterized by two different spectra of turbulence. The first one of them is well known Kolmohorov spectrum, which describes the plasma with zero mean magnetic field. The second one is the Kraichnan spectrum with a different from zero mean magnetic field. Transition from one spectrum type to another one occurs at scale of 3 Mm.We have to note that the scale 3 Mm corresponds to one of mesogranulation and testifies about non-zero mean magnetic fields for the consideration of regions exceeding the granulation in active regions of the photosphere. Besides, this clears the possibility of appearance of selforganizing magnetic plasma structures such as spots, active regions and complexes of activity. Title: Properties of convective motions in facular regions Authors: Kostik, R.; Khomenko, E. V. Bibcode: 2012A&A...545A..22K Altcode: 2012arXiv1207.4340K
Aims: We study the properties of solar granulation in a facular region from the photosphere up to the lower chromosphere. Our aim is to investigate the dependence of granular structure on magnetic field strength.
Methods: We used observations obtained at the German Vacuum Tower Telescope (Observatorio del Teide, Tenerife) using two different instruments: the Triple Etalon SOlar Spectrometer (TESOS) to measure velocity and intensity variations along the photosphere in the Ba ii 4554 Å line; and, simultaneously, the Tenerife Infrared Polarimeter (TIP-II) to the measure Stokes parameters and the magnetic field strength at the lower photosphere in the Fe i 1.56 μm lines.
Results: We find that the convective velocities of granules in the facular area decrease with magnetic field while the convective velocities of intergranular lanes increase with the field strength. Similar to the quiet areas, there is a contrast and velocity sign reversal taking place in the middle photosphere. The reversal heights depend on the magnetic field strength and are, on average, about 100 km higher than in the quiet regions. The correlation between convective velocity and intensity decreases with magnetic field at the bottom photosphere, but increases in the upper photosphere. The contrast of intergranular lanes observed close to the disk center is almost independent of the magnetic field strength.
Conclusions: The strong magnetic field of the facular area seems to stabilize the convection and to promote more effective energy transfer in the upper layers of the solar atmosphere, since the convective elements reach greater heights. Title: Magnetic field effect on the fine structure of convective motions in the solar atmosphere Authors: Kostyk, R. I. Bibcode: 2012KPCB...28..155K Altcode: No abstract at ADS Title: Some properties of convective motions in the upper solar atmosphere. II Authors: Kostyk, R. I. Bibcode: 2011KPCB...27..175K Altcode: No abstract at ADS Title: Peculiarities of convective motions in the upper solar atmosphere. I Authors: Kostyk, R. I. Bibcode: 2010KPCB...26..233K Altcode: No abstract at ADS Title: Solar granulation from photosphere to low chromosphere observed in Ba II 4554 Å line Authors: Kostik, R.; Khomenko, E.; Shchukina, N. Bibcode: 2009A&A...506.1405K Altcode: 2009arXiv0909.1210K Aims: The purpose of this paper is to characterize the statistical properties of solar granulation in the photosphere and low chromosphere up to 650 km.
Methods: We use velocity and intensity variations obtained at different atmospheric heights from observations in Ba II 4554 Å. The observations were done during good seeing conditions at the VTT at the Observatorio del Teide on Tenerife. The line core forms rather high in the atmosphere and allows granulation properties to be studied at heights that have been not accessed before in similar studies. In addition, we analyze the synthetic profiles of the Ba II 4554 Å line by the same method computed taking NLTE effects into account in the 3D hydrodynamical model atmosphere.
Results: We suggest a 16-column model of solar granulation depending on the direction of motion and on the intensity contrast measured in the continuum and in the uppermost layer. We calculate the heights of intensity contrast sign reversal and velocity sign reversal. We show that both parameters depend strongly on the granulation velocity and intensity at the bottom photosphere. The larger the two parameters, the higher the reversal takes place in the atmosphere. On average, this happens at about 200-300 km. We suggest that this number also depends on the line depth of the spectral line used in observations. Despite the intensity and velocity reversal, about 40% of the column structure of granulation is preserved up to heights around 650 km. Title: Observations of a bright plume in solar granulation Authors: Kostik, R. I.; Khomenko, E. V. Bibcode: 2007A&A...476..341K Altcode: Aims:The aim of this paper is to analyze the thermal properties, oscillatory, and flow motions of a bright, long-lasting feature observed in solar granulation, which we call the plume.
Methods: We used the spectral observations of quiet granulation at solar disc center, including the two Fe II 5234 and Fe I 6393 Å lines recorded simultaneously at the German Vacuum Tower telescope in Tenerife. The recorded data revealed a stable, bright structure of 3-4 arcsec size present during the whole 2.5 h of observations. We compare the velocity fields extracted by means of a λ-meter method and temperature and pressure stratification obtained after inversion of the profiles related to granules, intergranular lanes, and the plume.
Results: The following results were obtained: (i) the correlation between variations in convective velocity and intensity in the plume is close to zero at all observed heights; (ii) the velocity flow in the plume changes from a downflow in the deep layers to an upflow in the upper layers; (iii) the brightness of the plume increases with height; (iv) the amplitudes of the five-minute oscillations of intensity and velocity are twice lower in the plume than outside, and vertically propagating waves are observed; (v) the plume is hotter and denser than the quiet Sun in the upper photosphere.
Conclusions: We conclude that the observed phenomenon has a non-convective origin. The decrease in the amplitudes of oscillations in the plume cannot be attributed to the higher density in comparison to the surrounding atmosphere. Along with other findings, this indicates the possible presence of magnetic field. Title: Fine structure of wave motions in the solar photosphere: Observations and theory Authors: Kostyk, R. I.; Shchukina, N. G.; Khomenko, E. V. Bibcode: 2006ARep...50..588K Altcode: Spectral observations of the 639.361-nm FeI line at the center of the quiet solar disk with high spatial (0.4″) and temporal (10 s) resolution are used to investigate the behavior of local 5-min oscillations over granules and intergranular lanes. The power of the 5-min oscillations in the upper photosphere (at heights of H ≈ 490 km) is higher the faster the convective motions in the lower photosphere (H ≈ 10 km). This suggests that turbulent convection is responsible for the excitation of local solar oscillations. A statistical analysis of the oscillations shows that, on average, both the intensity and velocity of the oscillation amplitudes are greater over intergranular lanes. This difference in amplitudes is present throughout the studied heights in the photosphere (H = 0-490 km). The period at which the power spectrum of velocity oscillations reaches its maximum is longer over intergranules than over granules. Simulations of the propagation of acoustic-gravity waves in an atmosphere taking into account the convection pattern give a satisfactory explanation for the above observed effects. It is concluded that the atmospheric modulation of the 5-min oscillations is an additional or alternative mechanism responsible for differences between these oscillations over granules and intergranules. Title: Bright features in the solar photosphere Authors: Kostik, R. I.; Khomenko, E. V. Bibcode: 2005KFNTS...5..141K Altcode: We report thermodynamical properties of so-called ``thermal plume'' observed near the solar disc centre in 2001. The spectral observations of two iron lines analysed were obtained with the use of the Vacuum Tower Telescope (Tenerife). Title: Fine structure of convective motions in the solar photosphere Authors: Kostik, R. I. Bibcode: 2005KFNTS...5..134K Altcode: The granulation brightnesses and convective velocities in the solar photosphere between the levels of formation of the continuum radiation and the temperature minimum are examined. The properties of the brightness and velocity are analysed in a sixteen-column model. Four sorts of motions are most typical and efficient. In the first two, only the sign of the relative contrast of the material changes, which occurs, on the average, at a height of 270 km. In the last two motions, both the sign of the contrast and the direction of the motions are reversed near ∼350 km. The convective motions maintain their column structure throughout the photosphere, right to the temperature minimum. Title: Helioseismology space and ground-based studies Authors: Kostik, R. I.; Osipov, S. N.; Khomenko, E. V.; Lebedev, N. I. Bibcode: 2005KFNTS...5..138K Altcode: We give a preliminary report on the observations of solar irradiance fluctuations with the DIFOS photometer aboard the Russian-Ukrainian satellite CORONAS-F launched in 2001. In addition, the parallel ground-based spectral observations (VTT, Tenerife) carried out with 20-day observing space campaign are described. Title: The Helioseismological CORONAS-F DIFOS Experiment Authors: Lebedev, N. I.; Kuznetsov, V. D.; Oraevskii, V. N.; Staude, J.; Kostyk, R. I. Bibcode: 2004ARep...48..871L Altcode: The CORONAS-F DIFOS experiment continues the CORONAS-I studies started in 1994, devoted to investigations of solar global oscillations. CORONAS-F was launched July 31, 2001. Variations in the intensity of the solar radiation are measured in the six spectral intervals of the multi-channel photometer: 350, 500, 650, 850, 1100, and 1500 nm, with the bandwidths being about 10% of the central wavelength of each interval. The scientific goals of the experiment, a brief description of the instrument, and observational conditions are presented, as well as the data processing techniques. The first observations of the low-order p eigenmodes of the solar oscillations are presented for various wavelength ranges. A decrease in the relative amplitudes with observing wavelength is indicated. The amplitude ratios for various spectral ranges agree well with those detected earlier in ground-and space-based experiments. Title: Fine Structure of Convective Motions in the Solar Photosphere: Observations and Theory Authors: Kostyk, R. I.; Shchukina, N. G. Bibcode: 2004ARep...48..769K Altcode: The granulation brightnesses and convective velocities in the solar photosphere between the levels of formation of the continuum radiation and the temperature minimum are examined. Spectral images of the granulation observed in lines of neutral and ionized iron with high spatial (0.5″) and temporal (9 s) resolutions were obtained using the German Vacuum Tower Telescope in Izana (Tenerife, Spain). A correlation analysis shows that the granules and intergranules change their relative brightness at a height near 250 km, and a general reversal of the velocity occurs near a height of 490 km, where the material above granules begins to predominantly descend, and the material above intergranules, to ascend. The maximum correlation coefficient between the velocity and the line brightnesdoesnot exceed 0.75. The properties of the brightness and velocity are analyzed in a sixteen-column model. Four sorts of motions are most typical and efficient. In the first two, only the sign of the relative contrast of the material changes (an efficiency of 46%). This occurs, on average, at a height of 270 km. In the last two motions, both the sign of the contrast and the direction of the motion are reversed near a height of 350 km (an efficiency of 28%). All the observed dependences are compared with theoretical relations obtained in a three-dimensional hydrodynamical model, with deviations from local thermodynamic equilibrium included in the calculation of the spectral-line profiles. This model can satisfactorily reproduce all the basic features of the convective velocities and intensities. It is concluded that the convective motions maintain their column structure throughout the photosphere, right to the level of the temperature minimum. This makes a separation of the photosphere into two regions with different granulation brightnesses and convective motions unjustified. Title: Convective and wave motions in a thermal plume Authors: Kostik, Roman I.; Khomenko, Elena V. Bibcode: 2004IAUS..223..271K Altcode: 2005IAUS..223..271K Here we report thermodynamical properties of a a so-called "thermal plume" observed near the solar disc center in 2001. The spectral observations of two iron lines analysed have been obtained using the Vacuum Tower Telescope (Tenerife). Title: Helioseismology space and ground based studies Authors: Kostik, R. I.; Osipov, S. N.; Khomenko, E. V.; Lebedev, N. I. Bibcode: 2004IAUS..223..273K Altcode: 2005IAUS..223..273K This is a preliminary report on the observations of solar irradiance fluctuations with the DIFOS photometer aboard the Russian-Ukrainian satellite CORONAS-F launched in 2001. In addition the parallel ground-based spectral observations (VTT, Tenerife) carried out with the first 20-days observing space campaign are described. Title: The Effect of Acoustic Waves on Spectral-Line Profiles in the Solar Atmosphere: Observations and Theory Authors: Kostyk, R. I.; Khomenko, E. V. Bibcode: 2002ARep...46..925K Altcode: The fine structure of the FeI λ 532.4185-nm line of neutral iron is studied with high spatial (0.5″) and temporal (9.3 s) resolution using observations of a quiet region at the center of the solar disk. The character of the line asymmetry depends strongly on the nature of the velocity field, i.e., on whether it is due to convective or wave motions. The magnitude of the asymmetry due to acoustic waves is comparable to that due to convective motions. The propagation of acoustic waves in moving granules and intergranular lanes is studied by solving a system of hydrodynamical equations in a three-dimensional model for the solar atmosphere. The temporal variations in the bisector of the line synthesized in a non-LTE approximation agree well with the observational data. Title: Global Oscillations of the Sun in a Wide Optical Spectral Range: DIFOS Experiment Onboard CORONAS-F Authors: Oraevsky, V.; Lebedev, N.; Kuznetsov, V.; Staude, J.; Kostyk, R. Bibcode: 2002cosp...34E.345O Altcode: 2002cosp.meetE.345O The DIFOS experiment onboard the CORONAS-F spacecraft continues the investigation of solar global oscillations, which was started in 1994 during the CORONAS-I mission. The satellite was launched on July 31, 2001. It uses a multi-channel photometer to observe irradiance fluctuations. The photometer measures fluctuations of the solar flux in six optical spectral ranges: near 350, 500, 650, 850, 1100, and 1500 nm with a bandwidth of about 10% of the central wavelength for each. After a short description of the instrumentation and data analyses, we present results of observations of low-degree p-modes of global oscillations for different observational optical ranges. The oscillation amplitudes were found to decrease with the growth of the wavelength. The amplitude ratios for different wavelength are in a good agreement with earlier observations and theoretical predictions. Title: Five-minute oscillations above granules and intergranular lanes Authors: Khomenko, E. V.; Kostik, R. I.; Shchukina, N. G. Bibcode: 2001A&A...369..660K Altcode: We discuss the links between the photospheric 5-min oscillations and the granulation pattern using a 30-min time series of CCD spectrograms of solar granulation recorded with high spatial (0{''}5) and temporal (9.3 s) resolution. The observed images contain the Fe \sc{i 5324 Å spectral line with good height coverage from the low photosphere up to the temperature minimum region. Amplitudes, phases and periods of the 5-min oscillations are found to be different above granules and intergranular lanes. Strong oscillations occur well separated temporally and spatially. Many features of this different behaviour can be described in the frame of a relatively simple model of wave propagation in the solar atmosphere. To that aim, we have introduced oscillations into a 3D snapshot of a theoretical time dependent solar model atmosphere. NLTE synthesis of the time series of the Fe \sc{i 5324 Å line profiles was performed taking into account granular and oscillatory components of the velocity field. Both, observations and theoretical modeling, lead to similar results: (i) oscillations above granules and intergranular lanes occur with different periods; (ii) the most energetic intensity oscillations occur above intergranular lanes; the most energetic velocity oscillations occur above granules and lanes with maximum contrast, {i.e.} above the regions with maximum convective velocities; (iii) velocity oscillations at the lower layers of the atmosphere lead oscillations at the upper layers in intergranular lanes. In granules the phase shift is nearly zero. We conclude that differences in oscillations above granules and lanes are caused mainly by variations of the physical conditions in these structures. Title: Granulation and five-minute oscillations Authors: Khomenko, E. V.; Kostik, R. I.; Shchukina, N. G. Bibcode: 2000KFNTS...3..431K Altcode: We discuss the links between the photospheric 5-min oscillations and granulation patterns using a 30-min time series of CCD spectral images of solar granulation recorded with high spatial (0.5'') and temporal (9.3 s) resolution. The observed images contain Fe I 5324 Å line. Our observations and theoretical modeling lead to the similar results: (i) period of oscillations varies above granules and lanes; (ii) amplitudes of the velocity oscillations grow with the contrast of granulation. Amplitudes of the intensity oscillations are larger in intergranular lanes than in granules. Our simple model describes the basic features of the oscillations above granules and intergranular lanes. We conclude that differences in these oscillations are caused mainly by variations of the physical conditions in these structures. Title: Interaction of Granulation with the 5-min Photospheric Oscillations Authors: Kostik, R. I.; Shchukina, N. G.; Khomenko, E. V. Bibcode: 1999ESASP.448..319K Altcode: 1999ESPM....9..319K; 1999mfsp.conf..319K No abstract at ADS Title: Local 5-min oscillations above solar granules and intergranular space Authors: Kostyk, R. I.; Shchukina, N. G. Bibcode: 1999AstL...25..678K Altcode: A time series of granulation spectral images with high spatial (less than 0.5 arcsec) and temporal (9.3 s) resolutions has been obtained with the German vacuum tower telescope (VTT) on the Canary Islands in an effort to study the local 5-min solar oscillations. Observations were carried out with a CCD array in the FeI lambda 532.4185-nm line.The 5-min intensity and velocity fluctuations near the temperature minimum, where this line originates, are shown to respond differently to the fine photospheric structure. The most energetic velocity fluctuations occur above the regions where the convective velocities are at a maximum; the main power of the velocity fluctuations above granules concentrates at lower frequencies than that in integranular space. The amplitude of the intensity fluctuations in the lambda 532.4185-nm emission above granules is, on the average, approximately a factor of 2 smaller. Title: Five-minute oscillations and fine structure of the solar photosphere. II. Authors: Kostyk, R. I.; Shchukina, N. G. Bibcode: 1999KFNT...15..135K Altcode: 1999KNFT...15..135K The evolution of spectra of the solar Fe I λ 532.4185 nm line averaged statistically over granules and intergranules of different brightness are studied. The observations were carried out with the Vacuum Tower Telescope at the Observatorio del Teide, Tenerife. The response to the fine structure of the lower photosphere turns out to be clearly different for the five minute oscillations of the velocity and the intensity observed in such spectra. The amplitudes of line intensity oscillations above intergranular lanes are nearly two times larger than over granules. The power spectrum of intensity oscillations is dominated by high-frequency oscillations, while the velocity oscillations gain power in the low-frequency band. The amplitudes of the velocity oscillations over granules and intergranules of the same brightness contrast are virtually equal. The most energetic velocity oscillations are shown to occur over areas where the largest convective velocities are observed. Title: Five-minute oscillations and the fine structure of the solar photosphere. I. Authors: Kostyk, R. I.; Shchukina, N. G. Bibcode: 1999KFNT...15...25K Altcode: 1999KNFT...15...25K The authors analyse the spatial relationship between the solar granulation and the local five-minute oscillations of velocity and intensity observed in the Fe I λ532.4185 nm line. The time series of CCD spectral images of solar granulation taken at the Germany Vacuum Tower Telescope (VTT) were recorded with high spatial (<0.5 arcsec) and temporal (9.3 s) resolution. In the temperature minimum region, where the line is formed, the most energetic intensity oscillations are shown to occur mainly over dark intergranular lanes, while strong velocity oscillations are observed over granules and intergranules. The amplitude of the latter oscillations increases with the granulation brightness contrast. The spatially averaged power of intensity oscillations is concentrated at higher frequencies compared to the power of velocity oscillations. Title: Five-minute oscillations and the fine structure of the solar photosphere. II. Authors: Kostyk, R. I.; Shchukina, N. G. Bibcode: 1999KPCB...15..102K Altcode: The authors examine the evolution of the solar Fe I λ 532.4185 nm line spectrum averaged over granules and intergranular lanes of different brightness. The five-minute velocity and intensity oscillations observed in this spectrum are shown to occur differently over various fine-structure features in the photosphere. The amplitudes of line intensity oscillations above intergranular lanes are nearly twice as large as above granules. The bulk of the power of these oscillations fall on high frequencies, while the velocity oscillations gain their power in the low-frequency band. The velocity oscillation amplitudes are virtually equal over granules and dark lanes of the same brightness contrast. The most energetic velocity oscillations are observed over the areas with the highest convection velocities,. Title: Five-minute oscillations and the fine structure of the solar photosphere. I. Authors: Kostyk, R. I.; Shchukina, N. G. Bibcode: 1999KPCB...15...16K Altcode: The authors analyze the spatial relationship between the solar granulation and the local five-minute velocity and intensity oscillations observed in the Fe I λ532.4185 nm line. The spectral granulation images were recorded with high spatial and temporal resolution (<0.5 arcsec and 9.3 s) at the German Vacuum Tower Telescope. In the temperature minimum region, where the line is formed, the most energetic intensity oscillations occur mainly over dark intergranular lanes. Strong velocity oscillations are observed over granules and intergranules, their amplitude increasing with the granulation brightness contrast. The space-averaged intensity oscillation power is concentrated at higher frequencies compared to the power of velocity oscillations. Title: Diagnostic of the solar atmosphere using iron lines. Authors: Shchukina, N. S.; Kostyk, R. I.; Trujillo Bueno, J. Bibcode: 1998IBUAA..12Q..32S Altcode: No abstract at ADS Title: DIFOS helioseismological experiment. Authors: Kostyk, R. I.; Keselman, I. G.; Osipov, S. N.; Zhugzhda, Yu. D.; Kopaev, I. M.; Lebedev, N. I.; Oraevskij, V. N. Bibcode: 1998BCrAO..94..163K Altcode: The DIFOS solar telescope is intended for measuring variations of total solar radiation on board the KORONAS spacecraft launched 1994. Title: Problem of iron abundance in the solar photosphere. Authors: Kostyk, R. I.; Shchukina, N. G.; Rutten, R. J. Bibcode: 1998BCrAO..94..118K Altcode: The authors analyze the causes of the discrepancies. Title: High spatial resolution observations of the solar spectral lines. Authors: Kostyk, R. I.; Shchukina, N. G.; Briand, C. Bibcode: 1998IBUAA..12...39K Altcode: No abstract at ADS Title: The Scanner for Precise Spectrophotometry of the Sun as a Star Authors: Osipov, S. N.; Gandzha, S. I.; Andriyenko, O. V.; Karpov, M. V.; Kostik, R. I. Bibcode: 1997SoPh..172..361O Altcode: 1997ESPM....8..361O The primary shortcomings of existing methods for spectrophotometry of the Sun as a star are discussed. A new observational method is proposed. This method is based on a repeated scanning of the Sun's image while summing the signal of each step across the solar disk. A device for precise spectrophotometry of the Sun as a star has been developed around a double-pass spectrograph. This device and its operation algorithm are described. Errors caused by scanning irregularities and seeing are estimated. Several Sun-as-a-star spectrum line profiles and their bisectors are presented and compared with the same ones from the Kitt Peak FTS solar flux atlas. Title: The NLTE Formation of Iron Lines Used in Solar Polarimetry Authors: Shchukina, Nataliya G.; Bueno, Javier Trujillo; Kostik, Roman I. Bibcode: 1997SoPh..172..117S Altcode: 1997ESPM....8..117S We study in some detail one-dimensional NLTE effects in solar Fei lines. The lines selected are frequently used in solar polarimetry, and also in studies of line asymmetries and for abundance determinations. Our model atom for Fei-Feii-Feiii is realistic: it takes account of multiplet structure and it includes over 200 bound-bound and bound-free transitions in detail. We use very efficient iterative methods for the self-consistent solution of the kinetic and radiative transfer equations (Auer, Fabiani Bendicho, and Trujillo Bueno, 1994). We have applied these fast methods of solution because they are suitable for the investigation of 2D and 3D NLTE transfer effects with multilevel atoms, which constitutes the next step of our ongoing research project on the iron line formation problem. Title: The Instrumentation of the Main Astronomical Observatory of the National Academy of Sciences of Ukraine Authors: Kostik, R. I.; Shchukina, N. G. Bibcode: 1997ASPC..118..372K Altcode: 1997fasp.conf..372K The instrumentation and observational programs of the Solar Physics Department of the Main Astronomical Observatory are described. The observatory has two solar horizontal telescopes. The first one is the 44 cm telescope located near Kyiv. This telescope has a spectrograph with a double pass system. It was designed for low scattered light and high spectral resolution. The second one is installed at Terskol High-Altitude Station in the Central Caucasus, at an altitude of 3100 m. This 65 cm telescope with its spectrograph is used for simultaneous photoelectric and photographic measurements of five solar spectral regions in the range from 3000 Angstroms to 12000 Angstroms. One of the scientific programs consists in the observation of solar irradiance fluctuations with the DIFOS photometer aboard the Ukraine-Russian satellite CORONAS-I, which was launched on March 2, 1994. These space observations will be continued during the new mission CORONAS-F. Title: On a new method of obtaining the Sun-as-a-star spectrum Authors: Osipov, S. M.; Andriyenko, O. V.; Gandzha, S. I.; Karpov, N. V.; Kostik, R. I. Bibcode: 1997MmSAI..68..463O Altcode: No abstract at ADS Title: The solar iron abundance: not the last word. Authors: Kostik, R. I.; Shchukina, N. G.; Rutten, R. J. Bibcode: 1996A&A...305..325K Altcode: Determinations of the solar iron abundance have converged to the meteoritic value with the FeII studies of Holweger et al. (1990), Biemont et al. (1991) and Hannaford et al. (1992) and the FeI results of Holweger et al. (1991). However, the latter authors pointed out that Blackwell et al. (1984) obtained a discordant result from similar oscillator strengths. A recent debate on this lingering discrepancy by the Oxford and Kiel contenders themselves has not clarified the issue. We do so here by showing that it stems from systematic differences between equivalent widths and oscillator strengths which masquerade as difference in fitted damping enhancement factors. We first discuss the various error sources in classical abundance determination and then emulate both sides of the debate with abundance fits of our own. Our emulation of the Oxford side shows that the abundance anomaly claimed by Blackwell et al. (1984) for solar FeI 2.2eV lines vanishes when equivalent width measurements from other authors are combined with better evaluation of the collisional damping parameter. On the Kiel side, we find that the oscillator strengths of Bard et al. (1991) used by Holweger et al. (1991) produce a suspicious trend when used to fit solar FeI lines, whereas comparable application of oscillator strengths from Oxford does not. The trend is mainly set by categories of FeI lines not measured at Oxford; for lines of overlap the two sets agree and deliver the iron abundance value A_Fe_=7.62+/-0.04 which exceeds the meteorite value. The dissimilar lines may suffer from solar line-formation effects. We conclude that the issue of the solar iron abundance remains open. Definitive oscillator strengths are still needed, as well as verification of classical abundance determination by more realistic representations of the solar photosphere and of photospheric line formation. Title: Device for precise spectrophotometry of the Sun as a star. Authors: Gandzha, S. I.; Osipov, S. N.; Karpov, N. V.; Kolokolova, L. O.; Kostyk, R. I. Bibcode: 1996KPCB...12a..71G Altcode: 1996KPCB...12...71G A device for precise spectrophotometry of the Sun as a star has been developed around a double-pass solar monochromator. The device and its operation algorithm are described. Errors caused by scanning irregularities and seeing are estimated. Some results of test observations are presented. Title: Is the problem of solar iron abundance solved? Authors: Kostik, R. I.; Shchukina, N. G. Bibcode: 1995AdSpR..15g..69K Altcode: 1995AdSpR..15...69K We revise the solar photospheric abundance of iron from Fe I lines based on two scales of oscillator strengths gf (Oxford [1-6] and Kiel [7]). In order to answer the question of Holweger et al. [8] why the gf of both scales agree but abundances deviate, we analyse different sources of errors in the solar iron abundance determinations. The most important reason of the abundance discrepancy is connected with the damping enhancement factor, E. However, the results obtained do not allow to infer a final value of the solar iron abundance. The ``high'' abundance derived from the Oxford scale of gf [2] seems to be more preferable in view of a smaller root mean square error epsilon in the iron abundance determination and a more pronounced minimum of the function epsilon(E) in comparison with the ``low'' abundance case [8]. Title: Solar Irradiance Oscillations: Preliminary Results of the Coronas-Difos Experiment Authors: Lebedev, N. I.; Oraevsky, V. N.; Zhugzhda, Y. D.; Kopaev, I. M.; Kostyk, R. I.; Pflug, K.; Rüdiger, G.; Staude, J.; Bettac, H. -D. Bibcode: 1995ESASP.376b.353L Altcode: 1995soho....2..353L; 1995help.confP.353L No abstract at ADS Title: First results of the CORONAS-DIFOS experiment. Space observations of solar irradiance oscillations. Authors: Lebedev, N. I.; Oraevsky, V. N.; Zhugzhda, Y. D.; Kopaev, I. M.; Kostyk, R. I.; Pflug, K.; Ruediger, G.; Staude, J.; Bettac, H. -D. Bibcode: 1995A&A...296L..25L Altcode: The DIFOS experiment aboard the satellite CORONAS has been designed to observe irradiance fluctuations due to global solar oscillations. The satellite was launched on March 2, 1994. It uses a photometer measuring fluctuations of the solar flux in three channels: near 550nm, 750nm, and from 400nm through 1.1μm. After a short description of the instrumentation and the data analysis we present first, preliminary results of observations of low-degree p-modes including their variation in time. Title: The Determination of the Solar Iron Abundance from Fe I Lines Authors: Kostik, R. I.; Shchukina, N. G.; Rutten, R. J. Bibcode: 1995ASPC...78..399K Altcode: 1995aapn.conf..399K No abstract at ADS Title: Space Helioseismology Experiment DIFOS Authors: Zhugzhda, Y. D.; Oraevsky, V. N.; Lebedev, N. I.; Kopaev, I. M.; Kostyk, R. I.; Keselman, I. G.; Osipov, S. N. Bibcode: 1995ASPC...76..436Z Altcode: 1995gong.conf..436Z No abstract at ADS Title: Does the iron abundance anomaly obtained from the 2.2 eV Fe I lines really exist in the solar atmosphere? Authors: Kostyk, R. I.; Shchukina, N. G. Bibcode: 1994KFNT...10...51K Altcode: 1994KNFT...10...51K No abstract at ADS Title: In memoriam Ernest Andreyevich Gurtovenko (10 December 1928 - 20 January 1994). Authors: Kostik, R. I. Bibcode: 1994SoPh..152D...6K Altcode: 1994SoPh..152.....K No abstract at ADS Title: Photometer ``difos'' for the study of solar brightness variations Authors: Gurtovenko, E. A.; Kesel'Man, I. G.; Kostyk, R. I.; Osipov, S. N.; Lebedev, N. I.; Kopayev, I. M.; Orajevsky, V. N.; Zhugzhda, Yu. D. Bibcode: 1994SoPh..152...43G Altcode: 1994svs..coll...43G; 1994IAUCo.143...43G A photometer has been designed for measuring solar irradiance within three wide spectral bands with a relative error 0.00001 and time resolution of 16 sec. It is elaborated according to the international space project KORONAS and is planned to be launched at the begining of 1994. A description of its layout and operation is given briefly. Title: Is the problem of solar iron abundance solved? Authors: Kostyk, R. I.; Shchukina, N. G. Bibcode: 1994KFNT...10...54K Altcode: 1994KNFT...10...54K The authors revised the solar iron abundance from photospheric Fe I lines using two scales of oscillator strengths gf. The first one is Oxford high-precision laboratory measurements of Fe I transition probabilities. The second scale recently obtained in a hollow-cathode experiment by Bard et al. differs from the former by 0.03 dex in the absolute scale. The abundance values A = 7.64±0.04 and A = 7.50±0.07 respectively were determined. In order to explain the puzzle why gf of both scales agree but abundances deviate the authors have analysed the possible sources of errors in determinations of solar abundance. Title: Investigations of the Sun. Authors: Gurtovenko, Eh. A.; Kostyk, R. I. Bibcode: 1994maof.conf..189G Altcode: No abstract at ADS Title: Conference of the problem group "Radiation and structure of the Sun", held in L'vov, 23 - 25 September 1991. Authors: Gurtovenko, Eh. G.; Kostyk, R. I. Bibcode: 1992KFNT....8...91G Altcode: 1992KNFT....8...91G No abstract at ADS Title: Time variability of absorption lines in the solar spectrum. Authors: Kostyk, R. I. Bibcode: 1991KFNT....7...48K Altcode: 1991KNFT....7...48K The conclusion of Babij (1991) obtained from an analysis of variation of central depths of Fraunhofer lines observed in 1960 - 1985 seems to be doubtful. The conclusion is that up to some level (in the region where weak absorption lines are formed) the solar photosphere is in stationary state, and above that level the solar photosphere may be considered as unstationary. Title: Variability with time of absorption lines in the solar spectrum. Authors: Kostyk, R. I. Bibcode: 1991KPCB....7e..43K Altcode: 1991KPCB....7...43K B. T. Babii's conclusion (1991) that the Sun's photosphere is in a stationary state up to a certain level (in the formation region of weak absorption lines) and nonstationary above that level, which was obtained from analysis of the variations of Fraunhofer-line central depths observed in 1960 - 1985 is placed in doubt. Title: Fine structure of the Fraunhofer lines - Observation results and their interpretation Authors: Atroshchenko, I. N.; Gadun, A. S.; Kostyk, R. I. Bibcode: 1990KFNT....6R...3A Altcode: Observation results on line asymmetry and absolute line shift in the spectra of the solar photosphere are presented and their theoretical interpretation is discussed. Empirical data are presented on the line asymmetry and line shifts for the center of the solar disk, for center-to-limb transition, for the spectrum of the sun as a star, and for active regions. Data are also presented concerning variations of line asymmetry as a function of the phase of the solar cycle. The semiempirical approach to the interpretation of Fraunhofer line asymmetry and absolute line shifts is also discussed. The results of a multidimensional numerical simulation of convective motions in the superadiabatic region and in the solar photosphere are presented. Title: Fine structure of the Fraunhofer lines: observation results and their interpretation. Authors: Atroshchenko, I. N.; Gadun, A. S.; Kostyk, R. I. Bibcode: 1990KNFT....6R...3A Altcode: The review embraces results of the spectral line observations and their theoretical interpretation. The empirical data on the line asymmetry and absolute wavelength shifts are presented for the solar centre, for different positions on the solar limb and for the Sun as a star. Their dependence on the phase of the solar activity cycle is also reviewed. Interpretation of these data on the basis of semiempirical models is discussed. The multidimensional numerical simulation results of convective motions in the superadiabatic region and in the solar photosphere are presented. Title: Analysis of Absorption Line Profiles in the Spectra of the Sun and Procyon - Velocity Field and Size of Inhomogeneities Authors: Gadun, A. S.; Kostyk, R. I. Bibcode: 1990SvA....34..260G Altcode: No abstract at ADS Title: Analysis of absorption line profiles in the solar and Procyon spectra : velocity field and sizes of turbulent eddies. Authors: Gadun, A. S.; Kostyk, R. I. Bibcode: 1990AZh....67..520G Altcode: It is shown that the turbulent velocity and the sizes of turbulent eddies in the Procyon atmosphere are 1.5-2.5 times larger than in the solar atmosphere. A comparative analysis of the variation of these parameters with height revealed substantial differences between convection processes on the sun and Procyon. Title: Statistical Regularities in the Solar Spectrum Authors: Kostyk, R. I.; Perekhod, A. V. Bibcode: 1990SvAL...16..111K Altcode: No abstract at ADS Title: Statistical regularities in the solar spectrum Authors: Kostik, R. I.; Perekhod, A. V. Bibcode: 1990PAZh...16..260K Altcode: The paper examines the dependence of halfwidth and equivalent width for Fe I lines on their excitation potential observed in the solar spectrum (Babiia, 1988). It is shown that the dependence can be explained within the framework of the modern theory of the formation of spectral lines. Title: Comparative Analysis of Physical Conditions in the Solar and Procyon Atmospheres Authors: Atroshchenko, I. N.; Gadun, A. S.; Kostik, R. I.; Pikalov, K. N. Bibcode: 1990IAUS..138..421A Altcode: No abstract at ADS Title: Solar Oscillator Strengths as a Diagnostic Tool Authors: Gurtovenko, E. A.; Kostik, R. I.; Rutten, R. J. Bibcode: 1990IAUS..138...35G Altcode: No abstract at ADS Title: New solar oscillator strengths from Kiev Authors: Gurtovenko, E. A.; Kostik, R. I.; Rutten, R. J. Bibcode: 1990asos.conf...92G Altcode: No abstract at ADS Title: Modeling of convective motions in the envelope of procyon. II. Asymmetry of the spectral lines Authors: Atroshchenko, I. N.; Gadun, A. S.; Kostyk, R. I. Bibcode: 1989Ap.....31..765A Altcode: 1990Ap.....31..765A No abstract at ADS Title: Modeling of convective motions in the envelope of procyon. I. ideology and analysis of three-dimensional models Authors: Atroshchenko, I. N.; Gadun, A. S.; Kostyk, R. I. Bibcode: 1989Ap.....31..580A Altcode: 1990Ap.....31..580A No abstract at ADS Title: Three-Dimensional Simulation of Convective Motions in the Procyon Envelope Authors: Atroshchenko, I. N.; Gadun, A. S.; Kostik, R. I. Bibcode: 1989ASIC..263..521A Altcode: 1989ssg..conf..521A No abstract at ADS Title: Solar spectroscopy. Authors: Jackiv, J. S.; Kostyk, R. I.; Schukina, N. G. Bibcode: 1989Rise...70...12J Altcode: No abstract at ADS Title: Asymmetry of Absorption Lines in the Solar and Procyon Spectra Authors: Atroshchenko, I. N.; Gadun, A. S.; Kostik, R. I. Bibcode: 1989ASIC..263..135A Altcode: 1989ssg..conf..135A No abstract at ADS Title: The Simulation of the Convective Motions in the Procyon Envelope - Part Two - Spectral Line Asymmetries Authors: Atroschenko, F. N.; Gadun, A. S.; Kostyk, R. I. Bibcode: 1989Afz....31..589A Altcode: No abstract at ADS Title: Fraunhofer spectrum and a system of solar oscillator strengths Authors: Gurtovenko, Ernest A.; Kostyk, Roman I. Bibcode: 1989KiIND.........G Altcode: Results of research concerned with the Fraunhofer spectrum of the sun and problems associated with this type of research are reviewed in a historical perspective. Solar dual-diffraction monochromators are described, and methods of observing the Fraunhofer spectrum with a high spectral resolution are discussed. Results of studies concerned with the development of solar oscillator forces, determined from the Fraunhofer lines, are reviewed. Oscillator force values are presented for 1958 spectral lines of 49 chemical elements in the wavelength range 303-996 nm. Title: Fraungoferov spektr i sistema solnechnykh sil ostsilliatorov Authors: Gurtovenko, Ernest Andreevich; Kostyk, Roman Ivanovich Bibcode: 1989fsss.book.....G Altcode: 1989QB551.G87...... No abstract at ADS Title: The simulation of the convective motions in the Procyon envelope. I. Ideology and analysis of the three-dimensional inhomogeneous models. Authors: Atroshchenko, I. N.; Gadun, A. S.; Kostyk, R. I. Bibcode: 1989Afz....31..281A Altcode: No abstract at ADS Title: Book Review: The galaxy and the solar system. / U Arizona Press, 1986. Authors: Kotov, V. A.; Kostik, R.; Shchukina, N.; Švestka, Zdeněk; Kotov, V. A. Bibcode: 1988SoPh..115..203K Altcode: 1988SoPh..115..203S No abstract at ADS Title: Empirical gf-determination from the solar spectrum Authors: Rutten, Robert J.; Kostik, Roman I. Bibcode: 1988ASSL..138...83R Altcode: 1988IAUCo..94...83R; 1988pffl.proc...83R The reliability of Fe I and Fe II oscillator strengths determined empirically from optical solar lines is tested. A comparison is made between gfW fits to the equivalent widths and gfD fits to the depths of 354 Fe I lines and 22 Fe II lines for various combinations of input parameters. The resulting scatter diagrams provide a measure of the attainable precision. Title: Rotation of the Solar Atmosphere at Different Altitudes Authors: Gadun, A. S.; Kostyk, R. I.; Sheminova, V. A. Bibcode: 1987SvA....31..557G Altcode: No abstract at ADS Title: The rotation of the solar atmosphere at different altitudes Authors: Gadun, A. S.; Kostyk, R. I.; Sheminova, V. A. Bibcode: 1987AZh....64.1066G Altcode: A new method for determining the solar rotation velocity is proposed. A comparison was made between the observed central depths of Fraunhofer lines in the spectrum of the sun as a star and calculations based on center-limb observations. For altitudes in the range of 100-1100 km above the level of the continuous spectrum, the solar rotation velocity hardly changes. Title: The oscillator strengths of the lines of rare earth elements Authors: Glavnaia Astronomicheskaia Observatoriia; Kostyk, R. I.; Karpov, N. V. Bibcode: 1987KFNT....3...14G Altcode: The oscillator strengths of 76 lines of eight rare earth elements are determined from the observed equivalent widths and central depths of the solar Fraunhofer lines. A comparison is made between the present values and experimental values obtained over the last 10 yrs. Title: Oscillator strengths of rare earths. Authors: Karpov, N. V.; Kostyk, R. I. Bibcode: 1987KFNT....3...14K Altcode: Oscillator strengths for 76 lines of eight rare earths are determined from observed equivalent widths, and central depths of solar Fraunhofer lines. Title: Abundances of the elements of the palladium group in the solar atmosphere. Authors: Kostyk, R. I. Bibcode: 1987BSolD1987...92K Altcode: Abundances of five elements of the palladium group are determined in the solar atmosphere: A(Y) = 2.25±0.08, A(Zr) = 2.54±0.14, A(Nb) = 1.67±0.08, A(Mo) = 1.96±0.02, A(Tc) ≤ -0.6. Title: Estimation of technetium abundance in the solar photosphere. Authors: Kostyk, R. I.; Perekhod, A. V. Bibcode: 1986KFNT....2...38K Altcode: On the basis of the analysis of 8 short spectral regions of the undisturbed solar photosphere it is concluded that the technetium abundance in the solar atmosphere does not exceed lg A(Tc) = -0.6 on the scale lg A(H) = 12.0. Title: Oscillator strengths of iron lines. Authors: Kostyk, R. I.; Orlova, T. V. Bibcode: 1986KFNT....2...63K Altcode: Oscillator strengths of 380 iron lines have been determined from the observed central intensities and equivalent widths of the Fraunhofer solar lines with r.m.s. error not exceeding 12%. Title: Book reviews Authors: Gurtovenko, E. A.; Kostik, R. I.; Tlamicha, A.; Zerull, R.; Schadee, Aert; Mészáros, A.; Néeman, Y.; Giese, R. H.; Sinclair, A. T.; Kleczek, J.; Trendelenburg, E. A.; Hillebrandt, Wolfgang; Sehnal, L.; de Graaff, W.; Slottje, C.; Courvisier, T.; van Beek, H. F.; Baud, B.; de Jager, C.; Danby, J. M. A.; Somov, B. V.; Cassinelli, J.; Verbunt, F. Bibcode: 1986SSRv...44..177G Altcode: No abstract at ADS Title: Book-Review - Spectral Line Shapes Authors: Rostas, F.; Gurtovenko, E. A.; Kostik, R. I. Bibcode: 1986SSRv...44..177R Altcode: No abstract at ADS Title: The establishment of internally consistent solar scales of oscillatorstrengths and abundances of chemical elements. Zirconium. Authors: Gurtovenko, E. A.; Kostyk, R. I.; Orlova, T. V. Bibcode: 1986KFNT....2...20G Altcode: Oscillator strengths for 19 Zr I lines (r.m.s. error±0.078 dex) and 10 Zr II lines (±0.081 dex) are determined from observed equivalent widths and central depths of solar Fraunhofer lines. The analysis of the differences of oscillator strengths derived from equivalent widths and from central depths leads to the conclusion that the lines under study have no essential hyperfine structure. Title: Rotation of the solar photosphere from observations of central depthsof Fraunhofer lines. Authors: Gadun, A. S.; Kostyk, R. I.; Sheminova, V. A. Bibcode: 1985KFNT....1R..53G Altcode: The solar rotation velocity for different heliographic latitudes has been found from comparison of the central depths of Fraunhofer lines in the spectrum of the sun as a star with the central depths of the same lines at different distances from the solar centre. Title: The fine structure of Fraunhofer lines in the spectrum of the sun as a star. Authors: Gadun, A. S.; Kostyk, R. I. Bibcode: 1985KFNT....1...24G Altcode: 1985KFNT....1R..24G The Fraunhofer lines in the spectrum of integrated sunlight are shown to have asymmetries similar to the asymmetry of the spectrum of the solar disk centre. It is found that the asymmetry varies with line strength and does not practically depend on the lower level excitation potential, ionization degree and atomic weight. Title: Oscillator strengths for the lines of the iron group elements. Authors: Gurtovenko, E. A.; Kostyk, R. I.; Orlova, T. V. Bibcode: 1985KFNT....1....3G Altcode: The significance of the work on the establishment of the solar gf-scales for the Fraunhofer lines of the elements of the iron group is evaluated in general, and the results of the work are summed up. The information on the number of lines investigated is given as well as on the number of corresponding publications. The comparison of the solar gf-scales with the highest precision values of the oscillator strengths for selected lines obtained in Oxford gives the r.m.s. internal error of the solar gf-scales ≤0.07 dex. Title: On the establishment of internally consistent solar scales of oscillator strengths and abundances of chemical elements. VI. Neutral vanadium. Authors: Gurtovenko, E. A.; Kostyk, R. I.; Orlova, T. V. Bibcode: 1985KFNT....1...62G Altcode: Oscillator strengths of 55 lines of neutral vanadium are determined from equivalent widths of solar Fraunhofer lines using the procedure developed by the authors and reported in the previous papers. Title: Fine Structure of Fraunhofer Lines and the Structure of the Solar Atmosphere Authors: Kostyk, R. I. Bibcode: 1985SvA....29...65K Altcode: No abstract at ADS Title: Fine structure of Fraunhofer lines and the structure of the solar atmosphere Authors: Kostyk, R. I. Bibcode: 1985AZh....62..112K Altcode: On the basis of data on the fine structure (asymmetry) of weak Fraunhofer lines observed in the spectrum of the center of the solar disk, a semiempirical inhomogeneous model of the solar atmosphere is proposed which explains: (1) the fine structure of moderate and moderately strong Fraunhofer lines at the center of the solar disk; (2) the change in the sign of the asymmetry of absorption lines from positive to negative in the center-to-limb transition; (3) the asymmetry of absorption lines formed in a granule and a porule; (4) the weak dependence of the fine structure of Fraunhofer lines on the atomic parameters; and (5) the shifts of absorption lines at different distances from the center of the solar disk. A fundamental difference of the model from those proposed earlier is the absence of correlation between the direction of motion of convective elements and their brightness. Title: On the establishment of internally consistent solar scales of oscillator strengths and abundances of chemical elements. VII. Mn I. Authors: Gurtovenko, Eh. A.; Kostyk, R. I.; Orlova, T. V. Bibcode: 1984BSolD1984...85G Altcode: Oscillator strengths of 30 Mn I lines are determined up to ±(0.06 - 0.07) dex from the equivalent widths of solar Fraunhofer lines. Title: On the Establishment of Internally Consistent Solar Scales of Oscillator Strengths and Abundances of Chemical Elements - Part Seven - Mni Authors: Gurtovenko, E. A.; Kostik, R. I.; Orlova, T. V. Bibcode: 1984BSolD...9...85G Altcode: No abstract at ADS Title: Construction of Internally Consistent Scales of Solar Oscillator Strengths and Contents of Chemical Elements - Determination of Coi Oscillator Strengths from the Equivalent Widths of Fraunhofer Lines with Allowance for Their Hyperfine Structure Authors: Gurtovenko, E. A.; Kostyk, R. I.; Orlova, T. V. Bibcode: 1983SvA....27..439G Altcode: No abstract at ADS Title: Construction of internally consistent scales of solar oscillator strengths and contents of chemical elements Determination of CO I oscillator strengths from the equivalent widths of Fraunhofer lines with allowance for their hyperfine structure Authors: Gurtovenko, E. A.; Kostik, R. I.; Orlova, T. V. Bibcode: 1983AZh....60..758G Altcode: The authors use the observed equivalent widths of 50 Co I lines and cobalt abundance lg A = 4.98 to derive the oscillator strengths (gf) of these lines. In addition, for 14 lines from the total list the oscillator strengths (gfHFS) were obtained with accounting for their hyperfine structure. Clear dependences of the difference lg gf - lg gfHFS on equivalent width and excitation potential are revealed. Using these dependences, the authors have corrected all the oscillator strengths obtained without accounting for the hyperfine structure. Title: Oscillator strengths of lines of ionized titanium and chromium Authors: Kostyk, R. I.; Orlova, T. V. Bibcode: 1983AAfz...49...39K Altcode: Oscillator strengths for 27 Ti II lines and 29 Cr II lines in the solar atmosphere were determined with an accuracy of + or - 0.15 dex. Estimates of titanium and chromium concentrations in the solar atmosphere are presented. Title: Mesoturbulence Authors: Kostyk, R. I. Bibcode: 1983AAfz...48...10K Altcode: It is shown that the mean velocity of mesoturbulent motions in the solar photosphere (the Kubo-Anderson processing being used) is depth-independent and amounts to xi = 1.75 km/s. The correlation length decreases with height from 750 km (lg tau = 0.8) to 350 km (lg tau = -1.7). The relation xi-squared = v-squared(micro) + v-squared(macro) is accurately satisfied for the photosphere. Title: Sizes of Turbulence Elements in the Solar Atmosphere Authors: Kostyk, R. I. Bibcode: 1982SvA....26..703K Altcode: No abstract at ADS Title: Sizes of turbulence elements in the solar atmosphere Authors: Kostyk, R. I. Bibcode: 1982AZh....59.1167K Altcode: The sizes of turbulent vortices at different heights in the solar atmosphere are determined. It is assumed that the sizes of turbulent vortices are distributed in accordance with a Poisson law while their velocities obey a Gaussian law. The number of turbulence elements occurring along a length having an optical depth of unity in the continuum, the root-mean-square velocity, and the correlation length are found from well-known spectral relationships and a described calculation procedure. It is found that the average size of turbulent vortices in the solar atmosphere decreases with height from 670 to 440 km, while their root-mean-square velocity is constant and equal to 1.7 km/s. Title: Empirical NLTE analyses of solar spectral lines. III - Iron lines versus LTE models of the photosphere Authors: Rutten, R. J.; Kostik, R. I. Bibcode: 1982A&A...115..104R Altcode: We compare observational indications of departures from LTE in solar Fe I lines with published NLTE computations in the context of discrepancies between empirical LTE and NLTE models of the solar atmosphere. We find that the importance of departures from LTE in Fe I and similar spectra is often underestimated through neglect of opacity departures. We demonstrate with numerical experiments that the peculiarities of the LTE models are artifacts due to the neglect of NLTE departures; in particular, we so explain the Holweger-Müller LTE model quantitatively. However, we show also that the NLTE formation of most optical metal lines is fortuitously well-mimicked by LTE computation when using LTE models. Thus, LTE-derived metal abundances and empirical oscillator strengths happen to be fairly precise. The same may hold for the use of theoretical radiative- equilibrium models in stellar abundance determinations. Title: Oscillator strengths for neutral titanium lines Authors: Kostyk, R. I. Bibcode: 1982AZh....59..693K Altcode: No abstract at ADS Title: Oscillator Strengths for Neutral Titanium Lines Authors: Kostyk, R. I. Bibcode: 1982SvA....26..422K Altcode: No abstract at ADS Title: Damping Constant and Turbulence in the Solar Atmosphere Authors: Kostik, R. I. Bibcode: 1982SoPh...78...39K Altcode: In the region of the formation of weak and medium-strong lines, the microturbulence increases with height (Vver=0.7-0.9 km s-1, Vhor= 1.1-1.5 km s-1), the macroturbulence decreases (Vver=1.6-1.4 km s-1, Vhor= 2.4-1.5 km s-1), and the total velocity field (vertical component) is depth-independent (1.7 km s-1). The empirical damping constants for Fe, Ti, Cr, Ni lines are equal 1.3γ6, 1.7γ6, 1.6γ6, 1.6γ6, respectively. The correlation length (the Kubo-Anderson process has been used) in the solar photosphere is 520-550 km. Title: On the establishment of internally consistent solar scales of oscillator strengths and abundances of chemical elements. III - Oscillator strengths obtained from equivalent widths of 360 FeI lines Authors: Gurtovenko, E. A.; Kostik, R. I. Bibcode: 1982A&AS...47..193G Altcode: Oscillator strengths for 360 selected Fraunhofer lines were determined using the observed equivalent widths of those lines. The R.M.S. error of the gf-values obtained amounts to 0.06-0.07 dex. The comparison of oscillator strengths calculated from equivalent widths (w) and central intensity (d) shows the reliability of the methods used and of the underlaying data. The systematic increase of the difference log gfW - log gfd for strong lines of high excitation potential is noticeable. Title: Oscillator strengths for lines of neutral nickel. Authors: Kostyk, R. I. Bibcode: 1982AAfz...46...58K Altcode: The oscillator strengths of 175 Ni lines in the solar atmosphere were determined from central intensities of solar Fraunhofer lines. The accuracy of the determination was + or - 0.09 dex. Title: The oscillator strengths of ionized iron lines Authors: Kostyk, R. I.; Orlova, T. V. Bibcode: 1982AAfz...47...32K Altcode: The method used in calculating the strengths from the equivalent width is the same as that described by Gurtovenko and Kostyk (1980), where residual intensities were used. The values used for the velocity of the microturbulent motions and for the damping constant and iron abundance in the solar photosphere are consistent with the results obtained by Kostyk (1981). The calculations are carried out on the basis of the HOLMU model, described by Holweger and Muller (1974). The equivalent widths of the solar lines are taken from the studies of, among others, Biemont (1978) and Blackwell et al. (1980). A table giving the strengths of 59 lines is included. Title: Mesoturbulence in the Solar Atmosphere Authors: Kostik, R. I. Bibcode: 1982ASSL...96..105K Altcode: 1982spls.meet..105K No abstract at ADS Title: On the establishment of internally consistent solar scales of oscillator strengths and abundances of chemical elements. I. Oscillator strengths for 865 FeI lines iron abundance. Authors: Gurtovenko, E. A.; Kostik, R. I. Bibcode: 1981A&AS...46..239G Altcode: A method is developed for the establishment of internally consistent scales for solar abundances and oscillator strengths and used to deduce the solar iron abundance and the oscillator strengths for 865 Fe I lines. The method involves the calculation of L, defined as the product of the abundance with the oscillator strength, which can be inferred from the line profiles, equivalent widths, central intensities and the entire Fraunhofer spectrum of the specific chemical element. In the iron study, abundance and oscillator strengths are derived from unblended central intensities of lines in the region 4000-8000 A taking into account the influence of macroturbulence velocities. An average iron abundance of 7.525 + or - 0.007 is obtained from 266 weak and moderately strong lines appearing in the oscillator strength scale of May et al. (1974). The obtained abundance was then used to calculate the oscillation strengths of all 612 weak and moderate Fe I lines and the remaining strong lines to within + or - 0.035 dex. Title: On the Establishment of Internally Consistent Solar Scales of Oscillator Strengths and Abundances of Chemical Elements - Part Two - on the Errors of the Oscillator Strengths of FEI Lines in the Kurucz Authors: Gurtovenko, E. A.; Kostik, R. I. Bibcode: 1981A&A...101..132G Altcode: It is shown that the errors on the oscillator strengths of the Kurucz-Peytremann gf-scale depend in a regular way upon the excitation potential and gf-value. Oscillator strengths with small values of gf and large excitation potentials are underestimated, and vice versa. Especially strong underestimations (by ≍2 orders of magnitude) of the oscillator strengths take place for the lines with excitation potentials EPL > 4 eV and oscillator strengths log gf < -4.0. Title: Interpretation of Center-To Profiles of Weak Fraunhofer Lines Authors: Kostyk, R. I. Bibcode: 1981SvA....25..343K Altcode: No abstract at ADS Title: The interpretation of center-limb profiles of weak Fraunhofer lines Authors: Kostyk, R. I. Bibcode: 1981AZh....58..604K Altcode: Profiles of weak Fraunhofer lines have been analyzed under the assumption that nonthermal broadening and asymmetry of the lines are caused by wave and convective motions. A comparison of computed and observed line profiles shows that a horizontal flow with a velocity of 2.7 km/s exists on the major part of the sun's surface. The upflow velocity is 0.9 km/s, and the granule-intergranule temperature difference is about 330 K. Title: Oscillator strengths for lines of neutral chromium Authors: Kostyk, R. I. Bibcode: 1981AAfz...45....3K Altcode: Microturbulence and macroturbulence velocities and the damping constant in the solar atmosphere were determined from Fraunhofer lines of neutral chromium and found to equal 0.8 km/s, 1.1 km/s, and 2.0 gamma (6) respectively. Oscillator strengths of 123 Cr I lines have been determined with an accuracy of 0.19 dex. Title: On the Establishment of Internally Consistent Abundance-Oscillator Strength Scales Authors: Gurtovenko, E. A.; Kostik, R. I. Bibcode: 1980LNP...114..296G Altcode: 1980IAUCo..51..296G; 1980sttu.coll..296G No abstract at ADS Title: Formation of the Profiles of Absorption Lines in the Inhomogeneous Medium Authors: Kostik, R. I. Bibcode: 1980LNP...114...53K Altcode: 1980sttu.coll...53K; 1980IAUCo..51...53K No abstract at ADS Title: On the microturbulence in the solar photosphere. Authors: Kostik, R. I.; Orlova, T. V. Bibcode: 1979SoPh...62...89K Altcode: The velocity of microturbulent motions in the solar photosphere at the level of formation of weak Fraunhofer lines (h ∼ 150 km) is found to be 0.1 ± 0.2 km s−1. The observations have been performed with the double-pass spectrometer in Kiev. Apart from thermal motions and damping effects we have taken into account convective and wave motions when calculating the broadening of absorption lines. Title: Formation of absorption lines in an inhomogeneous medium Authors: Kostyk, R. I.; Perekhod, A. V. Bibcode: 1979AAfz...39...40K Altcode: Fraunhofer lines asymmetry and its variations have been studied by means of convection, acoustic wave, and temperature fluctuation mechanisms. The present work analyzes Fraunhofer line profiles employing all these three mechanisms. Emphasis is placed on horizontal motions in a convective cell. An asymmetry value obtained theoretically is less than that of the observed one. Title: Double-diffraction monochromator of the Kiev-Golosseevo Observatory with a digital system for automation of observations and solar-spectrum processing Authors: Gurtovenko, E. A.; Kostyk, R. I. Bibcode: 1979AAfz...39...88G Altcode: No abstract at ADS Title: Effect of a travelling sound wave on the profiles of spectral lines. V. Authors: Kostyk, R. I.; Perekhod, A. V. Bibcode: 1978AAfz...34....3K Altcode: The previous papers were concerned with the calculation of line-center intensity fluctuations and Fraunhofer line shifts caused by acoustic waves. The present paper deals with the calculation of the asymmetry of the contour of the absorption coefficient of Fe lines (with various lower-level excitation potentials) at various heights of the solar atmosphere. Calculations are carried out on the basis of the Harvard-Smithsonian reference atmosphere, assuming that the photosphere in locally homogeneous and optically thin; that waves propagate only in the vertical direction; and that the input equations are linear. It is shown that the asymmetry of Fe I lines with excitation potentials below 2 eV is negative, but is positive for excitation potentials greater than 3 eV. The asymmetry of Fraunhofer lines increases in the transition from the photosphere to the chromosphere, and decreases with increasing damping constant. Title: On the asymmetry of selected Fraunhofer lines. Authors: Kostik, R. I.; Orlova, T. V. Bibcode: 1977SoPh...53..353K Altcode: An analysis is made of the asymmetry of Fraunhofer lines observed with the double-pass monochromator of the horizontal solar telescope ASU-5 of the Main Astronomical Observatory of the Ukrainian Academy of Sciences. The conclusion is that the character of macromotion in the radial direction varies with height; in a tangential direction the motions at different depths are homogeneous. The asymmetry of weak lines is due to convection rather than to wave motions. Title: Shift of Fraunhofer lines in the solar spectrum. Authors: Kostyk, R. I. Bibcode: 1977AAfz...31...48K Altcode: No abstract at ADS Title: On the asymmetry of selected Fraunhofer lines. IV. Authors: Kostyk, R. I.; Orlova, T. V. Bibcode: 1977AAfz...33...51K Altcode: The asymmetry of nine Fe I and Ni I Fraunhofer lines was studied at five different positions on the solar disk (cos theta = 1, 0.80, 0.60, 0.44, and 0.28), in order to obtain information on macroturbulent motions in the tangential direction. Asymmetry was characterized by a single parameter, defined as the ratio of the third- and second-order central moments of the function 1 - r(lambda), where r(lambda) is the residual line intensity. For all positions, the asymmetry decreases as equivalent width increases. At the center-limb transition the asymmetry of each line decreases and changes sign at some distance from the center. At the limb all the lines have negative asymmetry. This reveals that in the photosphere there are horizontal macroscopic motions besides radial ones. Studying the behavior of the asymmetry along a line profile from core to tail reveals that weak lines and tails of strong lines are formed in deeper layers than the cores of strong lines. This points to the different character of macromotions in the photosphere. Title: On the interpretation of Fraunhofer-line profiles Authors: Kostyk, R. I.; Gerbil'Skaya, I. M. Bibcode: 1976SvA....20..704K Altcode: No abstract at ADS Title: On the interpretation of Fraunhofer-line profiles Authors: Kostyk, R. I.; Gerbil'Skaya, I. M. Bibcode: 1976AZh....53.1244K Altcode: No abstract at ADS Title: Asymmetry of the infrared triplet lines of oxygen and determination of the relative content of isotopes O17 and O18 in the solar photosphere Authors: Kostyk, R. I. Bibcode: 1976AZh....53..125K Altcode: No abstract at ADS Title: Asymmetry of the infrared triplet lines of oxygen and determination of the relative content of isotopes O17 and O18 in the solar photosphere Authors: Kostyk, R. I. Bibcode: 1976SvA....20...67K Altcode: No abstract at ADS Title: On the asymmetry of selected Fraunhofer lines. III. Authors: Kostyk, R. I.; Orlova, T. V.; Gerbilskaia, I. M. Bibcode: 1976AAfz...29...89K Altcode: The asymmetry of 10 Fraunhofer lines observed with a horizontal solar telescope and a double-diffraction monochromator is examined as a function of equivalent width and lower-level excitation potential. The lines, all produced by neutral species, span the spectral range from 5811.919 to 7807.916 A. During processing of the observational data, the line profiles were smoothed both before and after being corrected for instrument-contour error. It is found that the asymmetry is 'positive' for all lines except the oxygen IR triplet at 7771.954, 7774.177, and 7775.395 A. The results also show that the asymmetry does not depend on excitation potential and decreases as the equivalent width increases. Possible reasons for the last two findings are considered. Title: On the Possible Mechanism of Formation of Emission Rim in Hydrogen Filaments Authors: Kostik, R. I.; Orlova, T. V. Bibcode: 1975SoPh...45..119K Altcode: Hα filtergrams of the chromosphere show an emission rim in many hydrogen filaments. We suppose that formation of this rim is due to photospheric radiation reflected by the filament in the direction of the chromosphere. The calculations show that: (1) the maximum contrast of the rim relative to the undisturbed chromosphere amounts to 1.4; (2) the larger the optical thickness of the filament and the closer to the solar limb it is situated, the brighter and wider is the rim; (3) the rim was not observed in filaments whose heights exceeds 10000km above the chromosphere. These results are in close agreement with observations. Title: Profiles of selected Fraunhofer lines for different positions center-limb on the solar disk. Authors: Gurtovenko, Eh. A.; Kostyk, R. I.; Orlova, T. V.; Troyan, V. I.; Fedorchenko, G. L.; Morozhenko, N. N. Bibcode: 1975psfl.book.....G Altcode: No abstract at ADS Title: Profiles of selected Fraunhofer lines for various center-limb positions on the solar disk Authors: Gurtovenko, E. A.; Kostyk, R. I.; Orlova, T. V.; Troian, V. I.; Fedorchenko, G. L. Bibcode: 1975KiIND....Q....G Altcode: The profiles of 98 Fraunhofer lines are tabulated for five positions (cos theta equals 1.00, 0.80, 0.60, 0.44, and 0.28) on the disk of the quiet sun. The data are based primarily on observations in the wavelength range 5700 to 6400 A made with a double solar spectrometer. Title: Effect of a progressive sound wave on the profiles of spectral lines. 2: Asymmetry of faint Fraunhofer lines Authors: Kostyk, R. I. Bibcode: 1974amap.nasa...56K Altcode: The absorption coefficient profile was calculated for lines of different chemical elements in a medium with progressive sound waves. Calculations show that (1) the degree and direction of asymmetry depend on the atomic ionization potential and the potential of lower level excitation of the individual line; (2) the degree of asymmetry of a line decreases from the center toward the limb of the solar disc; and (3) turbulent motions 'suppress' the asymmetry. Title: On the Asymmetry of Selected Fraunhofer Lines, II Authors: Kostik, R. I.; Orlova, T. V. Bibcode: 1974SoPh...36..279K Altcode: The asymmetry of 11 absorption lines of neutral iron was determined from observations made with the double-pass system on the horizontal solar telescope Asu-5. An attempt was made to interpret this asymmetry in terms of progressive sound waves. The value of asymmetry computed theoretically was shown to be on average only 20 % of the observed value. Title: Influence of a progressive sound wave on the profiles of spectral lines. IV. Shift of the iron lines in the spectrum of the sun's centre. Authors: Kostyk, R. I. Bibcode: 1974AAfz...23...52K Altcode: No abstract at ADS Title: Matrix Equations of Radiation Diffusion. IV. Authors: Kostyk, R. I. Bibcode: 1973aars.conf..163K Altcode: No abstract at ADS Title: Asymmetry of Selected Fraunhofer Lines. I. Authors: Kostyk, R. I.; Orlova, T. V. Bibcode: 1973aars.conf..150K Altcode: No abstract at ADS Title: Effect of a traveling sound wave on the profiles of spectral lines. I. Central intensity oscillations of the Fraunhofer lines. Authors: Kostyk, R. I. Bibcode: 1973AAfz...18...94K Altcode: No abstract at ADS Title: Effect of progressive sound wave on the profiles of spectral lines. III. Shift of faint Fraunhofer lines. Authors: Kostyk, R. I. Bibcode: 1973AAfz...19...44K Altcode: No abstract at ADS Title: The Interpretation of Absorption-Line Shifts in the Solar Spectrum Authors: Kostik, R. I.; Orlova, T. V. Bibcode: 1972SoPh...26...42K Altcode: The shifts of Fraunhofer lines of different chemical elements in a homogeneous medium with a plane monochromatic progressive adiabatic sound waves are derived. The calculations indicate that lines of neutral elements (6 ⩽ χ0 ⩽ 14) with lower excitation potentials χ0i= 0-2 eV are red shifted, those with excitation potential χ0i= 4-12 eV are blue shifted, and with χ0i= 3 eV are both blue and red shifted. The lines of ions are shifted toward the blue. The shifts of Fraunhofer lines are found to decrease from the centre of the solar disk to the limb. These results agree qualitatively and quantitatively with observations. Title: Ionization and Excitation of Helium in Prominences. Authors: Kostik, R. I. Bibcode: 1972SvA....15..582K Altcode: No abstract at ADS Title: Effect of a progressive sound wave on the profiles of spectral lines. II. Asymmetry of faint Fraunhofer lines. Authors: Kostyk, R. I. Bibcode: 1972AAfz...17...50K Altcode: No abstract at ADS Title: Ionization and Excitation of Helium in Prominences. Authors: Kostik, R. I. Bibcode: 1971AZh....48..738K Altcode: No abstract at ADS Title: On the diffusion of the Lc-emission in prominences. Authors: Kostyk, R. I. Bibcode: 1971BSolD1971...80K Altcode: No abstract at ADS Title: On the asymmetry of selected Fraunhofer lines. Authors: Kostik, R. I.; Orlova, T. V. Bibcode: 1970AAfz....9..117K Altcode: No abstract at ADS Title: Matrix Equations of Radiation Diffusion. IV. Authors: Kostyk, R. I. Bibcode: 1970asas.book..163K Altcode: No abstract at ADS Title: The matrix equations of the diffusion of radiation. IV. Authors: Kostik, R. I. Bibcode: 1970AAfz....9..128K Altcode: No abstract at ADS Title: Asymmetry of Selected Fraunhofer Lines. I. Authors: Kostyk, R. I.; Orlova, T. V. Bibcode: 1970asas.book..150K Altcode: No abstract at ADS Title: Matrix equations of radiation diffusion. III Authors: Kostik, R. I. Bibcode: 1967Ap......3...76K Altcode: No abstract at ADS Title: Matrix equations for radiation diffusion. II Authors: Kostik, R. I. Bibcode: 1967Ap......3....6K Altcode: No abstract at ADS Title: Matrix equations for radiation diffusion. II. Authors: Kostik, R. I. Bibcode: 1967Afz.....3...17K Altcode: No abstract at ADS Title: Matrix equations for radiation diffusion. I Authors: Yakovkin, N. A.; Kostik, R. I. Bibcode: 1966Ap......2..197Y Altcode: No abstract at ADS