Search Publications
Dynamics of polar plumes observed during the total solar eclipse of August 1, 2008
Barczynski, K.; Rušin, V.; Saniga, M. +1 more
We study dynamics of polar plumes observed during the 2008 eclipse from three ground-based sites and the Hinode satellite. The speed of apparent upward propagation, as inferred from the changes of brightness within each plume, is found to lie in the range from 30 to 100 km s-1. Some white-light plumes located in polar coronal holes were…
Denoising observational data
Bourdin, Ph. -A.
Reducing noise caused by the instrumentation in observational data is a crucial step in data post-processing. A method is searched for that conserves most of the instrumental resolution and introduces as few methodical artefacts as possible. With such a method integrated in an observation sites software tool-chain, the resources spent for the gene…
Latitude-time distribution of the solar magnetic fields from 1975 to 2006
Minarovjech, M.
This paper presents the solar magnetic field distribution and meridional migration for the period of 1975-2006. A magnetic field latitude-time distribution map covering a 32-year period has been investigated. For this purpose a modified latitude-time diagram of the solar magnetic field distribution containing different kinds of fine structures is …
Effective temperatures of magnetic CP stars: semi-fundamental data
Stępień, K.; Lipski, Ł.
A brief discussion of earlier determinations of effective temperatures of chemically peculiar stars is given. It is stressed that the effective temperature is a global parameter, important for stellar structure and evolution studies. It should, however, be used with caution in atmospheric investigations. New determinations of effective temperature…
Bolometric correction of the roAp star αCir
Brandão, I. M.; Cunha, M. S.; Gameiro, J. F.
For the first time, the bolometric correction of α Cir was determined. Two values, both based on an estimation of the total integrated flux, were obtained. For that purpose spectroscopic and photometric data of α Cir available in the literature was used. The values derived were then used to place α Cir in the HR diagram.
Preliminary analysis of light curves of seven carbon stars
Mikulášek, Z.; Dušek, J.; Papoušek, J.
We present a preliminary analysis of the light curves of the following carbon stars: WZ Cas, VY UMa, Y CVn, RY Dra, T Lyr, HK Lyr and TT Cyg, constructed on the basis of our own BV photoelectric observations obtained at the Brno Observatory in 1979-94 and Hipparcos observations. The analysis suggests that "semiregular" light curves of all studied …
Photoelectric photometry of eclipsing contact binaries: U Peg, YY CrB, OU Ser and EQ Tau
Pribulla, T.; Vanko, M.
New photoelectric UBV observations of the eclipsing contact binary systems U Peg, YY CrB, OU Ser and EQ Tau obtained from August 2000 to October 2001 are presented and analyzed. The (O-C) diagram of U Peg indicates a decrease of the orbital period combined with a quasi-periodic variation. In the case of EQ Tau the long-term period changes can be i…
Eclipse observations of coronal plumes in the past and in future
Gulyaev, R. A.
Some historic fragments of eclipse investigations of polar coronal plumes are presented. New data of fundamental significance have been obtained recently thanks to the SOHO space observatory. Detection of polar plumes penetrating through the whole space of polar coronal holes is one of the most important results of the SOHO mission. It is suggeste…
Absolute magnitudes and kinematics of CP stars from HIPPARCOS data
Luri, X.; Figueras, F.; Torra, J. +5 more
The position in the HR diagram and the kinematic characteristics of different kinds of CP stars of the upper main sequence are obtained using the LM method of Luri et al. Most of the CP stars are main sequence stars occupying the whole width of the sequence. From a kinematic point of view, they belong to the young disk population (ages < 1.5 Gy…
Some recent results for the roAp stars
Kurtz, D. W.
Three topics are discussed: 1) Photometric observations of the rapidly oscillating Ap stars have shown that the pulsation amplitude drops dramatically as a function of wavelength from the blue to the red. A theoretical derivation, plus modelling, indicates that this is because the vertical wavelength of the pulsation mode is short compared to the …