The current software was developed at the Taurida National University, astronomy department of ph... more The current software was developed at the Taurida National University, astronomy department of physics faculty by Lyashko D.A., Tsymbal V.V. This programm comlex can be adapted according namely to individual spectrograph. All spectra processing goes automatically, so in this way it becomes possible to minimize user interaction with programm. It is very convinient and does not require special training for using it. In this case we can exclude human element and so then, output data corruption. The algotithm of processing due to differences between spectrographs is described in this paper.
Context. One of the field stars, HD 61199, simultaneously observed with Procyon by MOST in 2004 s... more Context. One of the field stars, HD 61199, simultaneously observed with Procyon by MOST in 2004 showed δ Scuti type variations and in addition a longer period of about four days. Time resolved spectroscopy was obtained at the Thüringer Landessternwarte Tautenburg to help interpreting the photometry which, based on RV measurements, indicated a triple system. Aims. The goal of this work was to identifiy the δ Scuti star in this multiple system, to obtain fundamental stellar parameters of the individual components and to determine the orbital elements. Methods. Classical Fourier techniques – supported by least-squares multi-sine fits – have been applied to MOST photometry. The ground based spectroscopy was analyzed with the Broadening Function (BF) and Least-Squares-Deconvolution (LSD) techniques, and the orbital elements derived with KOREL and ORBITX. Results. The photometric and spectroscopic observations are compatible with a triple system consisting of a δ Scuti star as the most lu...
Aims:We investigate the abundance distributions of silicon and iron on the surface of HR 7224 and... more Aims:We investigate the abundance distributions of silicon and iron on the surface of HR 7224 and check for the presence of magnetic fields. We try further to find an explanation for the observed Balmer line variations, alternative to that by surface temperature gradients given in a previous article. Methods: Based on time series of more than 570 high-resolution spectra we investigate the abundance distribution of silicon and iron using the Doppler Imaging technique applying two independent program codes and using single and multiple components atmosphere models. We further calculate the combined effect of abundance changes of Si, Fe, and He on the Hβ line profile and compare it with the observations. The mean longitudinal magnetic field strength of HR 7224 is measured spectropolarimetrically. Results: The Doppler Imaging analysis of HR 7224 shows the presence of large silicon and iron spots on the star's surface, large gradients of the abundances of these elements, and hints to...
We investigate a spectroscopic time series of the oscillating Algol-type star TW Dra to derive ba... more We investigate a spectroscopic time series of the oscillating Algol-type star TW Dra to derive basic system and stellar parameters and to prepare for mode identification. From the orbital solution we derive precise masses and get disentangled spectra of the components by using KOREL. For the primary we derive about solar abundance. Computed LSD profiles show a puzzling picture of blue-to-red traveling bumps indicating a rich spectrum of nonradial pulsations. Three pulsation frequencies could be found by using FAMIAS. A first attempt of mode identification indicates that TW Dra shows high-degree modes in the range of l=7-12.
Reinvestigations of the short-period oEA star RZ Cas by using the “SHELLSPEC” code con- firm most... more Reinvestigations of the short-period oEA star RZ Cas by using the “SHELLSPEC” code con- firm most of the system parameters obtained by Lehmann & Mkrtichian (2008). Results from spectra obtained in 2001 point to a transient phase of rapid mass transfer and to the existence of dense circumprimary matter of disk-like structure, while results from spectra obtained in 2006 show that the system was in a quiet state during this period and can be modelled very well by two stars of which the secondary component fills its Roche lobe. The brightness distribution over the surface of the secondary can be described by a gravity darkening law that assumes two different exponents for hemispheres of different stars.
We have shown the possibility for modelling Li blend 6708 A, for two roAp stars, HD83368 and HD60... more We have shown the possibility for modelling Li blend 6708 A, for two roAp stars, HD83368 and HD60435, taking into account lithium spots on the surfaces of these rotating stars. REE spots were also included in calculations. Slow rotating star HD101065 (Przybyslski's star) give the possibility of scrupulous identification of REE lines blending Li line and estimation of 6Li/7Li ratio.
We report on first results obtained in the framework of a larger study of oEA stars, i.e. Algol-t... more We report on first results obtained in the framework of a larger study of oEA stars, i.e. Algol-type systems with oscillating components. We investigate an extended time series of high-resolution spectra of the oEA star RZ Cas taken in 2006. By comparing our model calculations with the observations, we try to determine the system and atmospheric parameters of RZ Cas. Starting values were obtained from uvby photometry and from an analysis of the mean out-of-eclipse spectra by means of the KOREL program. The fine tuning of the model was done using the modified SHELLSPEC code. With SHELLSPEC we determined an unusual large gravity darkening exponent of 0.5 for the secondary of RZ Cas. This value is far above the theoretical limit given by the Von Zeipel law but in good agreement with those obtained by Unno et al. in 1994. We attribute the large value of different large star spots on the front and back sides of the secondary with respect to the primary that exists in the result of mass-o...
We analyze time-series of highresolution spectra of RZCas, one of the brightest Algoltype stars w... more We analyze time-series of highresolution spectra of RZCas, one of the brightest Algoltype stars where the primary shows δ Sct-like oscillations. Our inverstigation uses a variety of methods like the KOREL program to derive the orbital solution and to decompose the spectra of the binary components, the SynthV program to derive the elemental abundances of both components from the mean, decomposed spectra, and finally the newly developed Shellspec07_inverse program to compute optimized stellar parameters from the composite line profiles observed at different orbital phases including the eclipse mapping. Spectra of RZ Cas have been taken at two different epochs. In 2006, the system can be well modeled without including any Algol-typical effects like a gas stream or an accretion annulus into the calculations. We have only to assume that the secondary of RZCas shows a large dark spot on its surface pointing toward the primary, presumably originating from a cooling mechanism by the enthalp...
We have considered the possibility for modeling of remarkable spectral feature 6708 λ for HD10106... more We have considered the possibility for modeling of remarkable spectral feature 6708 λ for HD101065 (Przybylski's star) in two ways - as a blend of Li and REE lines and as blend of REE lines only. We show by model calculations that Li lines absorb significantly in the range 6707.72-6708.02 λλ and resulting Li abundance 3.3 dex (in the scale lg N(H)=12.0) is near to the primordial value.
Publications of the Astronomical Society of the Pacific, 2006
ABSTRACT We present a high‐resolution () spectral atlas of the F5 Ib star α Per covering the 3810... more ABSTRACT We present a high‐resolution () spectral atlas of the F5 Ib star α Per covering the 3810–8100 Å region. The atlas, based on data obtained with the aid of the echelle spectrograph BOES fed by the 1.8 m telescope at Bohyunsan Observatory (Korea), is the ...
A field star, HD 61199 (V ~ 8), simultaneously observed with Procyon by the MOST (Microvariabilit... more A field star, HD 61199 (V ~ 8), simultaneously observed with Procyon by the MOST (Microvariability & Oscillations of STars) satellite in continuous runs of 34, 17, and 34 days in 2004, 2005, and 2007, was found to pulsate in 11 frequencies in the delta Scuti range with amplitudes from 1.7 down to 0.09 mmag. The photometry also showed variations with a period of about four days. To investigate the nature of the longer period, 45 days of time-resolved spectroscopy was obtained at the Thueringer Landessternwarte Tautenburg in 2004. The radial velocity measurements indicate that HD 61199 is a triple system. A delta Scuti pulsator with a rich eigenspectrum in a multiple system is promising for asteroseismology. Our objectives were to identify which of the stars in the system is the delta Scuti variable and to obtain the orbital elements of the system and the fundamental parameters of the individual components, which are constrained by the pulsation frequencies of the delta Scuti star. Cl...
The current software was developed at the Taurida National University, astronomy department of ph... more The current software was developed at the Taurida National University, astronomy department of physics faculty by Lyashko D.A., Tsymbal V.V. This programm comlex can be adapted according namely to individual spectrograph. All spectra processing goes automatically, so in this way it becomes possible to minimize user interaction with programm. It is very convinient and does not require special training for using it. In this case we can exclude human element and so then, output data corruption. The algotithm of processing due to differences between spectrographs is described in this paper.
Context. One of the field stars, HD 61199, simultaneously observed with Procyon by MOST in 2004 s... more Context. One of the field stars, HD 61199, simultaneously observed with Procyon by MOST in 2004 showed δ Scuti type variations and in addition a longer period of about four days. Time resolved spectroscopy was obtained at the Thüringer Landessternwarte Tautenburg to help interpreting the photometry which, based on RV measurements, indicated a triple system. Aims. The goal of this work was to identifiy the δ Scuti star in this multiple system, to obtain fundamental stellar parameters of the individual components and to determine the orbital elements. Methods. Classical Fourier techniques – supported by least-squares multi-sine fits – have been applied to MOST photometry. The ground based spectroscopy was analyzed with the Broadening Function (BF) and Least-Squares-Deconvolution (LSD) techniques, and the orbital elements derived with KOREL and ORBITX. Results. The photometric and spectroscopic observations are compatible with a triple system consisting of a δ Scuti star as the most lu...
Aims:We investigate the abundance distributions of silicon and iron on the surface of HR 7224 and... more Aims:We investigate the abundance distributions of silicon and iron on the surface of HR 7224 and check for the presence of magnetic fields. We try further to find an explanation for the observed Balmer line variations, alternative to that by surface temperature gradients given in a previous article. Methods: Based on time series of more than 570 high-resolution spectra we investigate the abundance distribution of silicon and iron using the Doppler Imaging technique applying two independent program codes and using single and multiple components atmosphere models. We further calculate the combined effect of abundance changes of Si, Fe, and He on the Hβ line profile and compare it with the observations. The mean longitudinal magnetic field strength of HR 7224 is measured spectropolarimetrically. Results: The Doppler Imaging analysis of HR 7224 shows the presence of large silicon and iron spots on the star's surface, large gradients of the abundances of these elements, and hints to...
We investigate a spectroscopic time series of the oscillating Algol-type star TW Dra to derive ba... more We investigate a spectroscopic time series of the oscillating Algol-type star TW Dra to derive basic system and stellar parameters and to prepare for mode identification. From the orbital solution we derive precise masses and get disentangled spectra of the components by using KOREL. For the primary we derive about solar abundance. Computed LSD profiles show a puzzling picture of blue-to-red traveling bumps indicating a rich spectrum of nonradial pulsations. Three pulsation frequencies could be found by using FAMIAS. A first attempt of mode identification indicates that TW Dra shows high-degree modes in the range of l=7-12.
Reinvestigations of the short-period oEA star RZ Cas by using the “SHELLSPEC” code con- firm most... more Reinvestigations of the short-period oEA star RZ Cas by using the “SHELLSPEC” code con- firm most of the system parameters obtained by Lehmann & Mkrtichian (2008). Results from spectra obtained in 2001 point to a transient phase of rapid mass transfer and to the existence of dense circumprimary matter of disk-like structure, while results from spectra obtained in 2006 show that the system was in a quiet state during this period and can be modelled very well by two stars of which the secondary component fills its Roche lobe. The brightness distribution over the surface of the secondary can be described by a gravity darkening law that assumes two different exponents for hemispheres of different stars.
We have shown the possibility for modelling Li blend 6708 A, for two roAp stars, HD83368 and HD60... more We have shown the possibility for modelling Li blend 6708 A, for two roAp stars, HD83368 and HD60435, taking into account lithium spots on the surfaces of these rotating stars. REE spots were also included in calculations. Slow rotating star HD101065 (Przybyslski's star) give the possibility of scrupulous identification of REE lines blending Li line and estimation of 6Li/7Li ratio.
We report on first results obtained in the framework of a larger study of oEA stars, i.e. Algol-t... more We report on first results obtained in the framework of a larger study of oEA stars, i.e. Algol-type systems with oscillating components. We investigate an extended time series of high-resolution spectra of the oEA star RZ Cas taken in 2006. By comparing our model calculations with the observations, we try to determine the system and atmospheric parameters of RZ Cas. Starting values were obtained from uvby photometry and from an analysis of the mean out-of-eclipse spectra by means of the KOREL program. The fine tuning of the model was done using the modified SHELLSPEC code. With SHELLSPEC we determined an unusual large gravity darkening exponent of 0.5 for the secondary of RZ Cas. This value is far above the theoretical limit given by the Von Zeipel law but in good agreement with those obtained by Unno et al. in 1994. We attribute the large value of different large star spots on the front and back sides of the secondary with respect to the primary that exists in the result of mass-o...
We analyze time-series of highresolution spectra of RZCas, one of the brightest Algoltype stars w... more We analyze time-series of highresolution spectra of RZCas, one of the brightest Algoltype stars where the primary shows δ Sct-like oscillations. Our inverstigation uses a variety of methods like the KOREL program to derive the orbital solution and to decompose the spectra of the binary components, the SynthV program to derive the elemental abundances of both components from the mean, decomposed spectra, and finally the newly developed Shellspec07_inverse program to compute optimized stellar parameters from the composite line profiles observed at different orbital phases including the eclipse mapping. Spectra of RZ Cas have been taken at two different epochs. In 2006, the system can be well modeled without including any Algol-typical effects like a gas stream or an accretion annulus into the calculations. We have only to assume that the secondary of RZCas shows a large dark spot on its surface pointing toward the primary, presumably originating from a cooling mechanism by the enthalp...
We have considered the possibility for modeling of remarkable spectral feature 6708 λ for HD10106... more We have considered the possibility for modeling of remarkable spectral feature 6708 λ for HD101065 (Przybylski's star) in two ways - as a blend of Li and REE lines and as blend of REE lines only. We show by model calculations that Li lines absorb significantly in the range 6707.72-6708.02 λλ and resulting Li abundance 3.3 dex (in the scale lg N(H)=12.0) is near to the primordial value.
Publications of the Astronomical Society of the Pacific, 2006
ABSTRACT We present a high‐resolution () spectral atlas of the F5 Ib star α Per covering the 3810... more ABSTRACT We present a high‐resolution () spectral atlas of the F5 Ib star α Per covering the 3810–8100 Å region. The atlas, based on data obtained with the aid of the echelle spectrograph BOES fed by the 1.8 m telescope at Bohyunsan Observatory (Korea), is the ...
A field star, HD 61199 (V ~ 8), simultaneously observed with Procyon by the MOST (Microvariabilit... more A field star, HD 61199 (V ~ 8), simultaneously observed with Procyon by the MOST (Microvariability & Oscillations of STars) satellite in continuous runs of 34, 17, and 34 days in 2004, 2005, and 2007, was found to pulsate in 11 frequencies in the delta Scuti range with amplitudes from 1.7 down to 0.09 mmag. The photometry also showed variations with a period of about four days. To investigate the nature of the longer period, 45 days of time-resolved spectroscopy was obtained at the Thueringer Landessternwarte Tautenburg in 2004. The radial velocity measurements indicate that HD 61199 is a triple system. A delta Scuti pulsator with a rich eigenspectrum in a multiple system is promising for asteroseismology. Our objectives were to identify which of the stars in the system is the delta Scuti variable and to obtain the orbital elements of the system and the fundamental parameters of the individual components, which are constrained by the pulsation frequencies of the delta Scuti star. Cl...
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Papers by Vadim Tsymbal