Roots of astronomy in Bohemia reach into the history of Middle Ages. The astronomy and astrology was pursued on the royal courts of Czech Kings - well known examples are the richly illustrated manuscripts of king Wenceslas IV (14th cent.), the Al-Suphi atlas and others. Astronomy flourished at the Prague University (founded by the emperor Charles IV in 1348 as the first one in Central Europe) from the very beginning. It reached remarkable level e.g. in widely spread treatises "On the construction and On the use of astrolabe" by Cristannus de Prachaticz (1407) or in design of Prague Astronomical Clock (1410) by Johannes Schindel. The Prague astronomical school influenced its successors e.g. in Austria (Johannes von Gmunden) and Poland later highlighting the works of Regiomontanus and Copernicus respectively.

Further centuries brought evidence that the development of astronomy in Bohemia was based more on single outstanding scientific personalities than on a systematic institutional support. Very often the scientists spent only a part of their life in Bohemia. In 16th century, Cyprianus Leovitius became famous after he left Bohemia and became professor of astronomy at the University of Lauingen. Tycho Brahe lived in Bohemia for two years before his death in 1601. His received invitation to the Court of Emperor Rudolph II thanks to an initiative of Thaddeus Hagecius (Hájek). Tycho used Hagecius' positional observations of Nova Stella in Cassiopeia 1572 and of Great Comet 1577 to support the conclusion that both Nova 1572 and Comet 1577 were at larger geocentric distances than the Moon was. Johann Kepler accepted the invitation of Tycho and found laws of planetary motion, while evaluating Mars positions observed by Tycho Brahe. In the years 1600-1612 Kepler published numerous books and papers while staying in Prague, among them "Astronomia Nova" (containing his first and second laws), and texts on optics, on the "New star" of 1604 in constellation Ophiuchus, on his invention of astronomical telescope, on hexagonal structure of snow flakes and he wrote here also a phantasy about flight to the Moon "Dream or the Lunar astronomy". The three Prague Imperial Mathematicians, Nicolaus Raymarus Ursus, Tycho Brahe and Johann Kepler, together with the instrument makers Erasmus Habermel and Joost Bürgi (who was one of independent inventors of logarithms), marked significantly the time of late Renaissance during which Prague became a European crossroad of science and culture.

In the times of Thirty Years War, Ioannes Marcus Marci the physician, physicist, astronomer and mathematician at the Prague University, carried out experiments with the spectral dispersion of solar light passing through the water-filled vessels of different shapes (including prisma), studied colours of rainbow, soap bubbles and oil layers on the water. He found also isochronism of a pendulum, conservation of momentum and a few other things. His books on optics and mechanics appeared in press in Prague during 1648, two decades before Newton published results of similar experiments. Marci was elected to the Royal Society of London, but the messengers arrived late, after his death in 1667.

Among scientists working at Prague Clementinum, a Jesuit College, several outstanding astronomers should be mentioned: Caspar Pflieger, founder of the Mathematical Museum, the scientific instrument collections (1722), Joseph Stepling, founder of the Clementinum Observatory (ca 1750) and its first director, Jan Klein, the mechanician and watchmaker, Jan Tessanek who translated Newton's works and Antonin Strnad who started also the regular daily meteorological observations in 1775.

Growing international scientific communication and publication activities early in the 19th century only little affected Bohemia due to its at that time provincial position within the Austrian Habsburg monarchy. On one side, Martin Alois David, the director of Prague Clementinum Observatory, maintained lively correspondence with Franz von Zach (editor of the journal Monatliche Correspondenz); and Theodor Ambders Brorsen, the Danish astronomer at the observatory at Senftenberg Castle in East Bohemia, exchanged letters and observations with C. Schumacher (editor of Astronomische Nachrichten). On the other side, Christian Doppler - who was appointed professor of mathematics and practical geometry at the Prague Polytechnic University when he invented his famous principle in 1842 - published his important result only in a local Bohemian journal. Consequently, his principle was later "rediscovered" on other places (e.g. by H. A. Fizeau).

In the second half of 19th century, Ernst Mach, professor of Physics at the Prague University, contributed enormously to the education of a whole generation of both German and Czech physicists and astronomers. He experimentally studied the Doppler principle in acoustics and helped to the general recognition of Christian Doppler’s priority. After the Prague University was split into two independent universities in 1882, the Astronomical Observatory in Clementinum College became a part of the German university. The director Ladislaus Weinek devoted himself to the photography (e.g. Atlas of the Moon based on photographies from the Lick Observatory) and to the measurements of the pole height (in collaboration with Friedrich Küstner) that resulted into the discovery of the so called "polar motion".

The newly established Astronomical Institute of the Czech University (1886) found its seat in a garden house at Letná-quarter of Prague, and in 1900 it was moved into a villa in Švédská Street at Prague-Smíchov where it remained until 1997. August Seydler, its founder and the first director, elaborated sophisticated methods for the determination of orbits of minor planets. Textbooks on theoretical physics as well as many popular articles on astrophysics written by Seydler helped to maintain the general knowledge of that time that astronomy was an important part of not only science but also of culture. Seydler's successor Gustav Gruss observed variable stars and carried out visual observations of stellar spectra (in the last decade of 19th century). Two other variable-star observers of that time should be mentioned - Vojtěch Šafařík, professor at the Prague Charles University, and for 50 years younger Ladislav Pračka, both collecting their data mainly in their own private observatories.

Having only a scarce contacts to Czech physicists and astronomers, Albert Einstein spent one and half year (1911-1912) in Prague being appointed as professor at the German Prague University. It was his first professorship and he published in Prague 11 of his papers, including the first one on the deflection of light by the gravitational field of the Sun, containing formulation of the first fundamentals of the theory of General Relativity. Notably, his theory found an early support from the Czech scientists, astronomer Arnošt Dittrich (later Head the Konkoly Observatory in Ó Gyalla, now Hurbanovo, Slovakia ) and several professors of physics in Prague and Brunn.

When the independent Czechoslovak Republic was founded in 1918, the following basically professional astronomical institutions were acting on its territory:

1. The Ondřejov Observatory, founded in 1898 as a private observatory of brothers Josef and Jan Frič, owners of a small factory producing instruments of fine mechanics and optics. Josef devoted the building, equipment and scientific observing program to the memory of his brother Jan, who passed away shortly before the foundation. František Nušl, professor of astronomy at the Technical and Charles Universities, collaborated with Frič from the very beginning and became the director of the observatory after it was donated to the Czechoslovak Republic in 1928. Frič and Nušl developed an instrument for positional measurements called "circumzenithal" whose precision was quite comparable to that of the Danjon astrolabe which became more popular in other countries.

2. The State Observatory in Clementinum, already responsible only for the time keeping service and meteorological observations; the director became professor František Nušl. Its part was the observatory at Ó Gyalla (now Hurbanovo, Slovakia).

3. The Czech Astronomical Society (founded 1917), bringing professional and amateur astronomers together, that in 1928 built up and then operated a public observatory at the Petřín Hill of Prague. The Observatory bears the name of Milan Rastislav Štefánik, professional astronomer, who also became a politician and a general of the French army during World War I and was one of the founders of the Czechoslovak Republic (he died in his plane when returning home in 1919).

4. The Astronomical Institute of the Charles University in Prague-Smíchov, under the directorship of Vladimír Václav Heinrich, an expert on theoretical problems in celestial mechanics.

5. The Astronomical Institute of the German university in Prague, with an observing station in Telnitz (Erzgebirge).

After the Bolshevik Revolution in 1917, many scientists from the Russian territory found their new home in the Czechoslovak Republic, for instance the Ukrainian astronomer and physicist Ivan Puluj, or Vsevolod V. Stratonov, a former director of the Sternberg Institute in Moscow; both with some support from Jindřich Svoboda of the Technical University in Prague. A similar thing happened once more when Nazis came to the power in Germany in 1933 and many German scientists of Jewish origin flew from Germany via Czechoslovak Republic mainly to the USA. Erwin Finlay-Freundlich who continued to Manchester was one of them. A similar case was Zdeněk Kopal who left Czechoslovakia before World War II and worked in the USA and U.K. during the rest of his life.

From the middle decades of the 20th century, several astronomers should be mentioned like Vincent Nechvíle, holder of Lalande prize, with his achievements in optics and celestial mechanics, Erwin Finlay-Freundlich, who spent some time in Prague, and Zdeněk Kopal, author of early studies of close binaries and pioneer of lunar space research; later professor at Manchaster University.

A large development of astronomy in Czechoslovakia started after 1950 when Czechoslovak and Slovak Academy of Sciences were founded. Astronomical Institutes of Academy in Ondřejov and Praha and in Skalnaté Pleso / Tatranská Lomnica (founded during World War II by Czech astronomer A. Bečvář, famous for his Atlas Coeli) grow up steadily and the community of Czech and Slovak astronomers was strong and numerous enough by 1967 to host the General Assembly of the IAU in Prague. In 1959, the Czechoslovak Government approved the purchase of a Zeiss 2m telescope as a national observing facility and the telescope was located in Ondřejov and formally opened on the occasion of the General Assembly.

Following the Soviet-led military invasion to Czechoslovakia in 1968, several very productive and internationally well-recognised Czech astronomers like L. Kohoutek, M.J. Plavec, Z. Sekanina, Z. Švestka and later also I. Hubený left the country. For more then twenty years, official scientific collaboration of Czech astronomers with them was banned for political reasons. Yet, relatively rich professional contacts of Czechoslovak astronomers with the world astronomy were maintained even in this period. Thanks to this, Czechoslovakia was the first from all ex-socialist countries to join the large European Astronomical Journal Astronomy and Astrophysics, as an associate member in 1991, and a regular member since 1992.

The joint history of Czech and Slovaks in one state ended by 1992. Since January 1993, Czech Republic and Slovak Republic are two independent countries and also the astronomical facilities were divided. However, a very good cooperation between astronomical communities of both countries continues.

The politics of new leaders after 1989 is to support much larger proportion of research at the universities and to promote direct collaboration between various institutes and universities. The situation has been relatively favourable in astronomy since a contract of mutual collaboration has already existed for several decades between Astronomical Institute of the Academy of Sciences and Astronomical Institute of the Charles University, including also the usage of existing observational instruments.

At present, the research in astronomy and astrophysics in the Czech Republic is performed in several mutually cooperating institutions (listed below). The largest one is the Astronomical Institute of the Academy of Sciences of the Czech Republic (AI hereafter), one of about 60 research institutions of the Academy, covering many fields of science and humanities with their special budget yielded by the government. Next, there are universities financed through the Ministry of Education, also from the state budget. Finally, in the Czech Republic exists a network of observatories and planetariums supported by local districts and/or townships, the original main goal of which is the popularization and help to the ground and high schools in teaching of astronomy, but many of them also participate in programs of orignal astronomical research. Research teams in all these types of institutions can get an additional support from different granting agencies (e.g. GA of the Czech Republic, of the Academy of Sciences, of the Ministry of Education etc. as well as from some international foundations). The traditionally good level of popularization of astronomy, in which majority of professional astronomers participates, results also in strong amateur activities coordinated by the Czech Astronomical Society, a common society of amateurs and professionals, and also a few local societies. It forms also attracts students of astronomy and related topics at universities that also organise special 'schools' for younger students.

The universities are responsible for both undergraduate and postgraduate studies, however in both participate also many researchers from the Academy of Sciences by lecturing as well as by supervision of theses. On the basis of mutual agreement between the AI and the corresponding faculties in Prague and Brno, some PhD students perform their work directly in AI. On the other hand, some of the research activities at universities are supported also by cooperation with AI, especially when observational facilities are needed.

The facilities for ground-based optical observations are limited to the territory of Czech Republic and consequently suffer both from climatic conditions (typically 30% of clear sky) as well as from the light and other pollution. Top level data from large telescopes are obtained through a personal cooperation only. More regular approach to large instruments in more favourable conditions is the quest for future of the Czech astronomy.

Director: Jan Palouš (palous@ig.cas.cz)

Research areas:

This project involves studies of different atmospheric layers (photosphere, chromosphere, corona), evolution of the active regions including sunspots and the physics of solar prominences. Observational studies focus on: large-scale transport phenomena in the photosphere; the global flow patterns in the low atmosphere and convective zone (studied also with SOHO/MDI); the evolution of photospheric magnetic and velocity fields on smaller scales (magnetographic observations); fine structure of sunspots and granulation; chromospheric oscillations (SOHO/SUMER); research of prominences. At the Ondřejov Observatory the following ground observations are performed: longitudinal magnetic and velocity fields are measured in active regions by a magnetograph fed by an HSFA telescope and spectrograph Zeiss; prominence spectra are regularly detected by the Multichannel Flare Spectrograph (MFS) using the video CCD system; high-resolution observations are made on VTT (Tenerife) and SVST (La Palma). Important data also come from SOHO. The modernisation of two HSFA telescopes is almost finished:. HSFA1 is the magnetograph, HSFA2 will serve as a next-generation multichannel spectrograph, to replace the currently used MFS. These medium-size instruments will be used for special systematic observations (also as part of international campaigns such as the Max Millennium), which cannot be made with the largest telescopes. The group is involved in the so-called GREGOR project, the modernisation of the Gregory coudé telescope on Tenerife (German consortium).

YOHKOH, BATSE, SOHO, TRACE, the Max Millenium Flare program, HESSI, Solar-B projects are milestones in flare studies. The record of solar flares, eruptive prominences, their optical spectra and solar radio bursts are performed with the H-alpha telescope, the multichannel flare spectrograph and the 0.8-4.5 GHz radiospectrographs. Studies are devoted mainly to the following topics: pre-flare stages, primary flare energy-release processes, their radio and hard X-ray manifestations, chromospheric responses and their optical and UV spectroscopic diagnostics, flare magnetic field topology, initial stages of flare shock generation (precursors of type II bursts), eruptive prominences and coronal mass ejections and their evolution and structures. Numerical modelling, the analytical approach and the statistical data and image processing methods are used. The following numerical models have been developed: a hybrid 1-D hydro-radiative model for computing the chromospheric response during solar flares, non-LTE radiative transfer codes, 2-D and 3-D MHD models for simulating magnetic field reconnection and flare shock propagation, and 1-D and 3-D particle-in-cell models for special tasks of astrophysical plasmas. To fill in the gap in the hard X-ray observations a new hard X-ray spectrometer was developed and built (by Space Devices Ltd. in Prague). It was launched onboard the US MTI satellite on 12 March, 2000. The instrument provides full-disk observations of the solar hard X-ray emission in the region between 12 and 200 keV divided into 8 energy bands with a time resolution of 200 msec. The data will be available world-wide from the SolarSoft database.

The heliosphere and space weather has been attracting increasing attention in recent years because of its direct impact on the Earth’s environment and technological systems. The Institute has recently established a new research task that combines heliospheric research with various aspects of solar research to better respond to new challenges. Solar patrol observations regularly contribute to the world-wide monitoring system ISES together with our own solar-activity forecasts. Instruments for observing solar activity in white-light and H-alpha images, optical spectral lines, and radio waves are used in coordinated observations with instruments onboard the YOHKOH, SOHO/EIT, SOHO/LASCO, and WIND spacecraft. Various models have been developed for investigating different phenomena in the solar atmosphere, corona, and interplanetary space. These models have contributed to a better representation of the coronal magnetic field, studies of coronal shocks, interpretation of type II radio bursts, investigation of interplanetary shock and CME distortion in structured solar wind, and to the investigation of the internal structure and propagation of magnetic clouds in the heliosphere. Numerical simulations were also compared with IMP, WIND, and ULYSSES observations. The origin of coronal shocks and their propagation through the heliosphere are studied, photospheric magnetic field observations are incorporated in MHD models of the solar corona, 3-D models of CMEs including magnetic clouds are developed, and interconnection of different models is established. Simulations of coupled dynamic phenomena in the solar atmosphere and heliosphere, as well as selected space-weather events is performed.

P. Ambrož - large scale flows, coronal magnetic field;

V. Bumba - magnetic and velocity fields;

F. Fárník - X-ray space projects and X-ray analysis;

P. Heinzel - plasma spectroscopy and diagnostics, solar flare spectroscopy and modelling;

K. Jiřička - responsible for radio observations;

M. Karlický - magneto-hydrodynamics, plasma astrophysics and numerical modelling;

M. Klvaňa - magnetic and velocity fields;

P. Kotrč - spectral observations, solar flare spectroscopy and interpretations;

D. Odstrčil - MHD numerical modelling, coronal and interplanetary disturbances;

M. Sobotka - sunspots and granulation.

S. Šimberová - image processing;

M. Vandas - magnetic clouds and particle acceleration.

The research focuses on the problems of the dynamics of the Earth, dynamics of asteroids and tidal development of the planetary system. (e.g., the effect of high-order resonances on stable chaos of asteroids, the Modified Fourier Transform Method of studying chaos, importance of the three-body resonances, studies of Earth rotation in the Hipparcos reference frame, the effect of tidal evolution on the shapes of planetary satellites, etc.). The study of resonances in the asteroidal belt are made in order to explain the origin of Kirkwood gaps. The role of chaos became clear and the fast development of mathematical tools for studying chaotic trajectories followed; the overlap of orbital and secular resonances was found to be responsible for gaps. Chaotic diffusion and its importance is studied as well as the effects of high-order resonances in the structure of the asteroids. The methods of analysis of altimetric satellite measurements are developed for obtaining the Earth parameters and their long-term variations. In the first stage the TOPEX-POSEIDON altimetric data are studied to obtain long period variations of the Earth potential. Optical astrometry measurements have been re-reduced in the Hipparcos reference frame, and the Earth orientation parameters (EOP) determined in the interval 1899.7-1992.0. The same data were also used to link the Hipparcos Catalogue to the International Celestial Reference System. A new mathematical tool ("combined smoothing") has recently been developed to be used in combining the EOP as observed by modern space techniques (VLBI, GPS, SLR, LLR, DORIS). Since 2001 the group became Research Combination Centre of the International Earth Rotation Service (jointly with the Czech Technical University). EOP are analysed with respect to their geophysical excitations (atmosphere, oceans, ice coverage, groundwater storage, etc.).

The group relies on data both from older experiments (photographic fireball network, photographic spectroscopy, meteor radar) as well as on recently introduced new techniques (intensified video cameras, radiometer detectors, CCD cameras). The network of all-sky fireball cameras and spectral cameras has been in continuous operation since 1963 and is currently the only one in the world. A new program of CCD observations of asteroids using a dedicated 0.65m reflector started in 1993, with concentration on Near Earth Asteroids (NEA's). Following topics are studied: atmospheric fragmentation and structural properties of meteoroids, chemical composition of meteoroids from spectroscopy, physics of meteor radiation and ionization, long-term activity of meteor showers from radar observations, rotation of asteroids. New discoveries have been made in recent years: an asteroidal meteoroid in cometary orbit, several binary asteroids, very rapid rotation of an asteroid, differential ablation in Leonid meteors, and meteor radiation at an altitude of 200 km. The group participates in international cooperation, especially on asteroid observation, superbolides, and Leonid meteor campaigns. The research is now extended to both smaller and larger meteoroids and to NEA's in the sub-km size range. The efficiency and quality of observations and data reduction will also be improved by using automatic fireball cameras (currently being developed).

The most important conclusions resulting from observed orbital perturbations are atmospheric models which provide the spatial distribution and time variation of the thermosphere's density, as well as models of the Earth's albedo and infrared radiation distribution. One of them (TD88) was derived as a model which can be used to derive analytically satellite orbital perturbations of higher orders. In order to remove a general lack of the experimental data, the project "MIMOSA" (MIcroMeasurements of Satellite Acceleration) is in the final preparation stage before the launch of special microsatellite with an accelerometer as the only scientific instrument on board, expected in 2002. The calibrated variance-covariance matrix of a gravity field model is projected onto a radial orbit. The error and radial inaccuracy for various orbits, namely of altimetry satellites is investigated. The results show permanent progress from older to recent gravity field models; the radial error is not only smaller but its geographic variability is much lower than before. The methods used in theoretical studies are derived principally from considerations of classical celestial mechanics applied to the motions of close-earth bodies. The computational programs based on our theoretical results are produced. Combinations of the single and dual satellite crossovers have been found to be diagnostic tools for detecting residual signals of gravitational or non-gravitational origin in satellite crossover data.

Director: Petr Harmanec (petr.harmanec@mff.cuni.cz)

Astronomical Institute of the Charles University is an integral part of Faculty of Mathematics and Physics. Together with Institute of Theoretical Physics it forms a centre of theoretical physics and astronomy.

Education at Faculty of Mathematics and Physics is organised in such a way that all students are first educated in mathematics and physics and choose a specific discipline to study after fifth semester. Undergraduate students are therefore starting their astronomical education in the Astronomical Institute in the third year of their study at the Faculty of Mathematics and Physics and are supposed to finish their education at the faculty within five years, with a possibility to proceed more slowly and extend the study for one more year. During the last five years, more than 5 students graduated every year.

Some of the staff members of the Institute also organise and lead regular courses for teachers of physics at secondary schools and for students of the university of third age, are active in popularisation of astronomy and in book translations.

The research is performed in a close collaboration with the Institute of Theoretical Physics, AI, Silesian University at Opava, and with a number of foreign collaborators.

Students are educated thoroughly in mathematics and computing, and in all main branches of theoretical physics, including classical and quantum field theories, elementary particle physics, thermodynamics and statistical physics, solid state physics and, from the astronomical and astrophysical perspective most importantly, in relativistic physics, relativistic astrophysics and cosmology (4 hours lectures and 2 hours exercises per week over whole year). A number of special, 'selective' lectures are given on such topics as plasma physics, radiation theory, group theory, gauge theories etc. There are two traditional seminars organised every week, one on "Theoretical and Mathematical Physics", the other on "Relativistic Physics and Astrophysics". They are frequently given by foreign guests, among those astronomically oriented were S. Chandrasekhar, D. Novikov, M. Rees, D. Lynden-Bell, J. Ehlers, F. Chaffee and many others. A number of recognised Czech theoretical astronomers and astrophysicists were educated as theoretical physicists who later specialised in astronomy. On average during last 10 years about 10 students graduated in theoretical physics each year. The Institute is collaborating closely with several institutes of the Academy of Sciences of the Czech Republic, in particular with the Astronomical Institute, Institute of Physics, Institute of Plasma Physics, Institute of Nuclear Physics, Institute of Chemical Physics and Mathematical Institute. Members of these institutes give special lectures, supervise diploma and PhD theses, and participate in joint research projects.

Most of these (and also other) problems are solved in collaboration with relativists and astrophysicists abroad. The results are published in well-recognised journals as Phys. Rev. D, Phys. Rev. Letters, Monthly Not. R. Astr. Soc., Astrophys. J., Class. and Quantum Gravity, General Rel. and Grav., etc. A number of the papers have also been put on the web (gr-qc, astro-ph).

Director: Michal Lenc (lenc@physics.muni.cz)

Members of the Institute provide the complete courses of astronomy and astrophysics, general relativity and cosmology for all physics students, and specialised courses according to the scientific orientation (hot stars, variable stars, practical astrophysics) of the staff. They are also responsible for the major part of the bachelor studies of astrophysics.

The astronomical research is aimed mainly to the study of the physics of hot stars and stellar systems containing hot components. This research wants to contribute to the elucidation of the mutual relation among magnetic field geometry, spectroscopic and photometric spots or belts occurring on the surface of chemically peculiar (CP) stars. From both theoretical and observational points of view extended atmospheres of hot stars and their non-LTE models are studied, as well as stellar winds blowing from hot and luminous stars. Other fields of interest are: variable stars, carbon stars, K-type giants and properties of atmospheric extinction. Selected problems of the theoretical physics and relativistic astrophysics are also studied (energy-momentum tensor of classical electromagnetic fields; conservation laws in general relativity; exact solutions of Einstein's equations; electromagnetism in general relativity). The Institute manages the Masaryk University Observatory in Brno (Kraví hora), equipped with 0.6m reflector with a CCD camera.

J. Horský - general relativity, cosmology;

J. Krtička - hot stars;

Z. Mikulášek - hot stars, education;

J. Novotný - general relativity, cosmology;

Z. Pokorný - education;

V. Štefl - education.

Institute of Physics of the Silesian University at Opava

There is a Relativistic Astrophysics Group (abbreviated as RAG); it is a working group of staff members and students of physics at the Department of Physics, Faculty of Philosophy and Science, Silesian University, Opava, Czech Republic, that is scientifically active in the field of Relativistic Physics and Astrophysics.

1. Test particles and fields in black-hole backgrounds;
2. Accretion processes in the field of black holes and neutron stars;
3. Optical effects (light curves, line profiles) related to accretion discs;
4. Influence of a non-zero cosmological constant on the black-hole backgrounds;
5. Structure of neutron and quark stars (equation of state, rotation);
6. Cooling of neutron (quark) stars;
7. Oscillations of neutron (quark) stars;
8. Inflationary cosmology;
9. Cosmological models with decaying vacuum energy;
10. Einstein-Straus model of mass condensations in presence of a repulsive cosmological constant;
11. Anisotropies of relict background and Rees-Sciama effect.

The detailed account of RAG's activities can be viewed at http://uf.fpf.slu.cz/rag/.

Z. Stuchlík - relativistic astrophysics;

S. Hledík - relativistic astrophysics.

Director: Jan Kostelecký (kost@fsv.cvut.cz)

The center was established to solve the project of the Ministry of Education, Youth and Sports LN00A005 "Experimental Research of the Dynamics of the Earth and its Surface" and similar future projects in geodesy, Earth dynamics and deformations, applied geophysics, physical geography and close research areas. The center was founded by five research or education institutions:

• Research Institute of Geodesy, Topography and Cartography, Geodetic Observatory Pecný;
• Astronomical Institute of the Academy of Sciences of the Czech Republic;
• Department of Advanced Geodesy, Faculty of Civil Engineering, Czech Technical University in Prague;
• Department of Physical Geography and Geoecology, Faculty of Natural Science, Charles University in Prague;
• Institute of Rock Structure and Mechanics of the Academy of Sciences of the Czech Republic.

The astronomical part of the Center deals mainly with the satellite altimetry and Earth rotation, namely the International Earth Rotation Service Research Combination Center (responsible for proposing new algorithms to combine the Earth Orientation Parameters observed by different space techniques) is the part of the Center.

A. Čepek - theory of adjustment, mathematical treatment of data;

J. Klokočník - space geodesy, satellite altimetry;

J. Kostelecký - space geodesy, dynamics of the artificial Earth satellites;

L. Mervart - space geodesy, analysis of GPS observations;

I. Pešek - space geodesy, geodetic astronomy;

C. Ron - Earth rotation, astrometry;

J. Vondrák - Earth rotation, astrometry.

Czech Republic can be proud of its unique net of planetariums and people observatories their long-time educational and popularisation work is constantly admired. The aim of Czech people observatories and planetariums are primarily:

• to acquaint broad community with natural science knowledge;

• to develop and deepen hobbies in astronomy, astronautics, meteorology and other related sciences;

• to participate in extracurricular astronomical education of all age levels of pupils or students;

• to demonstrate scientific method by their specific astronomical research (including both observations and subsequent publishing of obtained results by a relevant way).

In the following sections there are given examples of scientific programme of several public observatories.

Research staff:

The Brno Observatory scientific programme is oriented to photoelectric photometry. The main observational instrument is a practically robotic telescope with 0.4 m primary reflector supplied with the CCD camera ST-7 and standard set of photometric filters of Kron-Cousine system. Observers (employees and voluntary co-workers of the Observatory, students of the Faculty of Science of Masaryk University in Brno) concentrate their attention to research of eclipsing binaries, cataclysmic stars and optical counterparts of Roentgen and gamma ray sources. Results are published predominantly in IBVS.

Brno Observatory is a leader and guarantee of the programme of visual observations of eclipsing binaries within Czech republic. With contributions of several tens of amateur observers there has been created an extended catalogue of times of minima of several hundred of variable stars. In the past was Brno the centre of amateur observations of meteors, too. Z. Mikulášek deals with cool chemically peculiar stars and atmospheric extinction, J. Dušek aims at photometric research of carbon stars.

The Observatory insists on cultivation of public, contemporarily namely by means of Internet. Collaborators of observatory take part in organising of Czech owners of CCD cameras, collect information dealing with unusual phenomena on the sky (UFOs), publish "advises to beginning observers". Extremely popular are the Brno Internet "Instant astronomical news" bringing up-to-date information on astronomical and astronautical achievements and events. IAN are issued two times in week.

Lunar occultation of stars and optionally occultation of stars by asteroids are recorded by TV CCD camera Oscar attached to the 335/1600 reflector. Insertion of scientific time signal into picture allows determination of absolute times of occultation with a accuracy of 0.02 s. Data on "total" occultation are annually postponed in International Lunar Occultation Center (Tokyo, Japan) which publishes them. Results of measurements of occultation by asteroids are sending continuously to International Occultation Timing Association and European Asteroidal Occultation Network. The Observatory occasionally organises expeditions for grazing lunar occultations. The results are continuously transmitted to IOTA. Drawings of solar photosphere in white light obtained by standard projection method are done here regularly and monthly sent to Solar Index Data Center.