Solar physics department

Hot NEWS: 

Reaching a better understanding of coronal mass ejections (CMEs) and their connection to the Sun’s surface is a major stake for space weather. Using state-of-the-art numerical simulations and space observations, a team of scientists from Paris Observatory – PSL and from the Astronomical Institute of the Czech Academy of Sciences discovered that, while CMEs propagate throughout the heliosphere, their core is continuously eroded and rebuilt all together, resulting in a drifting of their anchorage at the Sun’s surface. This unprecedented mechanism, that renews the historical standard model, is described in a series of articles published between January and December 2019 in Astronomy & Astrophysics and in the Astrophysical Journal. For more, see press release.


The Solar Physics Department studies our nearest star, the Sun, particularly the active phenomena in the solar atmosphere. This includes solar flares as well as accompanying heliospheric effects. Large-scale solar activity, evolution of solar active regions, the structure and evolution of sunspots and filaments, flare-energy storage, release and transport are studied. The research of the Solar Department can be characterized as a combination of computer-controlled solar observations in optical, radio and X-ray wavebands, analysis and interpretations of data, and theoretical research with extensive numerical modeling of the processes under study. All these activities are based on close cooperation with many institutes in Austria, Croatia, France, Germany, Holland, Italy, Japan, Poland, Russia, Slovakia, Spain and the U.S.A. This cooperation includes exchange of various data and their theoretical interpretation, as well as our participation in some of the ground-based and space projects.


The department has four working groups

Physics of solar flares and prominences

The group studies solar flares and prominences. We analyze and interpret the data observed at Ondřejov Observatory as well as the data observed from satellites (SOHO, TRACE, RHESSI, Hinode and so on.). We deal with the theory of solar spectroscopy and plasma, X-ray and radio astrophysics. We model numerically processes in solar flares and prominences.

Head: Jaroslav Dudík
Scientists:  Bartosz Dabrowski, Elena Dzifčáková, František Fárník, Stanislav Gunár, Petr Heinzel, Jana Kašparová, Pavel Kotrč, Hana Meszárosová, Dieter Nickeler, Pavol Schwartz, Jiří Štěpán, Michal Varady, Alena Zemanová, Maciej Zapiór


Structure and dynamics of the solar atmosphere

The group is dealing with physical conditions in the solar atmosphere, in active regions and in sunspots. Solar quiet and active regions at various atmospheric levels are studied in order to understand interactions between plasma motions and magnetic field. Medium (2") and very high (0.1" to 0.2") spatial-resolution observations in the optical region are used for this purpose. Global and large-scale dynamic properties of the Sun are studied, and horizontal transport velocities of plasma in the solar atmosphere are analyzed.

Head: Jiří Štěpán
Scientists: Pavel Ambrož, Jan Jurčák, Miroslav Klvaňa, Michal Sobotka, Michal Švanda 

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Heliosphere and space weather

The group studies dynamical phenomena in the solar wind, namely structure and propagation of coronal mass ejections (CME) and associated with them magnetic clouds, and interaction of the solar wind with bodies of the solar system. The research combines analyses of spacecraft observations with analytical modeling and numerical simulations using MHD, hybrid, and particle codes. The group is also involved in image information processing and improving its method. A part of the group is a small group of Solar Activity Monitoring and Forecasting. The group issues a weekly solar-activity forecast for a number of institutions and a daily solar-activity forecast for the media.

Head: Petr Hellinger
Scientists: Štěpán Štverák, Pavel Trávníček, Marek Vandas


Group of solar radioastronomy

The working group operates several radio telescopes at the Ondrejov observatory. Part of this group consists of ALMA ARC-CZ staff who are developing and supporting solar observations for the ALMA observatory.

Head: Artem Koval
Scientists: Miroslav Bárta, Marian Karlický, Wenjuan Liu, Galina Motorina



Department head: Jan Jurčák 
Deputy head: Jana Kašparová
Secretary: Alice Chytrová
tel.: +420 323 620 146
Address: Fričova 298, 251 65 Ondřejov, CZ