115 citations · 1.7k across the 100 of their papers we have counts for
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CNO driven winds of hot first stars
Jiri Krticka, Jiri Kubat
During the evolution of first stars, the CNO elements may emerge on their surfaces due to the mixing processes. Consequently, these stars may have winds driven purely by CNO elemen…
On the importance of the wind emission to the optical continuum of OB supergiants
Michaela Kraus, Jiri Kubat, Jiri Krticka
Thermal wind emission in the form of free-free and free-bound emission is known to show up in the infrared and radio continuum of hot and massive stars. For OB supergiants with mod…
Photometrically simply behaving mCP stars
Z. Mikulasek, T. Graf, J. Krticka +2
We analyzed uvby and Hp light curves of 19 well observed magnetic CP stars selected from the "On-line database of photometric observations of mCP stars" of which light curves in al…
The record-breaking rotational braking of the He strong CP star HD 37776
Z. Mikulasek, J. Krticka, J. Zverko +8
We study the long-term light and spectral variations in the He-strong magnetic chemically peculiar star HD 37776 (V901 Ori) to search for changes of its 1.5387 d period in 1976-200…
Wind emission of OB supergiants and the influence of clumping
Michaela Kraus, Jiri Kubat, Jiri Krticka
The influence of the wind to the total continuum of OB supergiants is discussed. For wind velocity distributions with β> 1.0, the wind can have strong influence to the total contin…
The light variability of the helium strong star HD 37776 as a result of its inhomogeneous elemental surface distribution
J. Krticka, Z. Mikulasek, J. Zverko +1
We simulate light curves of the helium strong chemically peculiar star HD 37776 assuming that the observed periodic light variations originate as a result of inhomogeneous horizont…
The ZOO of uvby and Hp light curves of magnetic chemically peculiar stars
Z. Mikulasek, J. Zverko, J. Krticka +3
We present preliminary results of the generalized Principal Component Analysis (PCA) of light curves of 82 magnetic chemically peculiar (further mCP) stars applied to 54 thousand i…
The light variations of HD 37776 as a result of the uneven surface distribution of helium and silicon
Jiri Krticka, Zdenek Mikulasek, Juraj Zverko +1
We calculate the uvby light curves of the helium-strong chemically peculiar (CP) star HD 37776. Assuming that the chemical peculiarity influences the monochromatic radiative flux d…
Hot star wind models with new solar abundances
Jiri Krticka, Jiri Kubat
We compare the hot star wind models calculated assuming older solar abundance determination with models calculated using the recently published values derived from 3D hydrodynamica…
Influence of the frictional heating on the wind line-profiles of SMC stars
Jiri Krticka, Daniela Korcakova, Jiri Kubat
We study the influence of the frictional heating on the wind line-profiles of SMC stars. For this purpose we use our NLTE wind code to obtain consistent occupation numbers of studi…
The Influence of X-ray Emission on the Stellar Wind of O Stars
Jiri Krticka, Jiri Kubat
We study the influence of X-ray radiation on the wind parameters of O stars. For this purpose we use our own NLTE wind code. The X-ray emission (assumed to be generated in wind sho…
Multicomponent radiatively driven stellar winds IV. On the helium decoupling in the wind of sigma Ori E
Jiri Krticka, Jiri Kubat, Detlef Groote
We study the possibility of the helium decoupling in the stellar wind of sigma Ori E. To obtain reliable wind parameters for this star we first calculate an NLTE wind model and der…
NLTE models of line-driven stellar winds II. O stars in SMC
Jiri Krticka
We calculate NLTE line-driven wind models of selected O stars in the spectral range of O4 to O9 in the Small Magellanic Cloud (SMC). We compare predicted basic wind properties, i.e…
Radiatively Driven Winds of OB Stars -- from Micro to Macro
Jiri Krticka, Jiri Kubat
We review basic physics of line-driven stellar winds of OB stars. We discuss elementary processes due to which stellar winds are accelerated on a microscopic level. We show how the…
Light variations and angular momentum loss from the He-strong magnetic chemically peculiar star HD 37776
Zdenek Mikulasek, Jiri Krticka, Juraj Zverko +2
We present a principle component analysis of multicolour light variations of the He-strong magnetic chemically peculiar star HD 37776 and its (O-C) diagram. The period increase rat…
The Nature of Light Variations of the He-Strong CP Star HD 37776
Jiri Krticka, Zdenek Mikulasek, Juraj Zverko +1
We calculated spectral energy distribution of the helium strong chemically peculiar star HD 37776 using adequate model atmospheres. We show that the chemical peculiarity influences…
NLTE wind models for SMC stars
Jiri Krticka
We study stellar wind properties of selected late O stars in the Small Magellanic Cloud (SMC). We calculate NLTE line-driven wind models for these stars and compare predicted wind…
The winds of the hot massive first stars
J. Krticka, J. Kubat
We study dynamical aspects of circumstellar environment around massive zero-metallicity first stars. For this purpose we apply our NLTE wind models. We show that the hydrogen-heliu…
Mass-loss and multicomponent flow from central stars of planetary nebulae
Jiri Krticka, Jiri Kubat
We calculate multicomponent radiatively driven stellar wind models suitable for central stars of planetary nebulae. Some of these stellar winds may be adequately modelled using one…
Properties and nature of Be stars XXIII. Long-term variations and physical properties of kappa Dra
S. M. Saad, J. Kubat, P. Koubsky +9
We present an analysis of new spectroscopic observations of the bright Be star kappa Dra obtained at the Ondrejov observatory during 1992 - 2003 and UBV photometric observations se…
Kinematic model inversions of hot star recurrent DAC data - tests against dynamical CIR models
J. Krticka, R. K. Barrett, J. C. Brown +1
The Discrete Absorption Components (DACs) commonly observed in the ultraviolet lines of hot stars have previously been modelled by dynamical simulations of Corotating Interaction R…
NLTE models of line-driven stellar winds I. Method of calculation and first results for O stars
Jiri Krticka, Jiri Kubat
New numerical models of line-driven stellar winds of late O stars are presented. Statistical equilibrium (NLTE) equations of the most abundant elements are solved. Properly obtaine…
Multicomponent stellar winds of He chemically peculiar stars
Jiri Krticka, Jiri Kubat
We calculate multicomponent stellar wind models with inclusion of a helium component applicable to He-rich and He-poor stars. We show that helium does not decouple from the stellar…
Modeling of multicomponent radiatively driven stellar winds using a Newton-Raphson method
J. Krticka
We present a simple method for the solution of one-component and multicomponent hydrodynamic equations based on the Newton-Raphson method. We show that this method can be used for…