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Start Over Creator Valníček, B.

2. Galvanoplastic grazing incidence mirrors for "vertical" experiments: the tandem tests in soft X-rays

Creator:
Hudec, R., Valníček, B., Šolc, I., Mitropolskii, M. M., Zhitnik, I. A., Krutov, V. V., and Sukhodrev, N. K.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
astrophysical experiments, soft X-rays, and grazing incidence mirrors
Language:
Czech
Description:
Described are the principles of calculation, the methodology and the results of laboratory tests of grazing incidence mirrors used in solar X-ray telescopes installed in rockets "Vertikal 8" (1979), "Vertikal 9" (1981) and "Vertikal 11" (1983) launched as part of the Intercosmos programme. The X-ray grazing incidence mirrors were developed in the Astronomical Institute of the Czechoslovak Academy of Sciences using galvanoplastic replica technology and tested in the Lebedev Institute of Physics of the USSR Academy of Sciences according to a chart design with one of the investigated mirrors acting as a collimator. The advantages and drawbacks of this test method of X-ray mirrors are analysed.
Rights:
http://creativecommons.org/publicdomain/mark/1.0/ and policy:public

3. Long-lasting X-ray emission from an active region

Creator:
Křivský, L., Fárník, F., Sudová, J., and Valníček, B.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
coronographs, active regions, and long-lasting X-ray emission
Language:
Czech
Description:
An exceptional 10-hour enhancement in the level of the soft X-ray emission, most probably originated in an exceptionally active region with flares at the eastern limb of the disk on Jan. 25, 1981, is described. This phonomenon has been called "an outstanding X-ray emission of an active region" (1984) and is documented by measurements made independently on two probes, i.e. GEQS-2 and PROGNOZ-8. The rise in the level of the X-ray emission (2-8 keV) amounted to about one order of magnitude (from l10^-6 to 10^-5 Wm^-2). The separate emission of flares are superimposed on this large enhancement. During the event, 3 outbursts were recorded int the 80 - 160 keV range, in each case at the time of recurrent flares in the region at the E limb (S 14, E 90) (Křivský and Scheirich, 1984). The most significant flares of this period were recorded by the coronograph on Lomnický štít. The flare had the form of ascending flare loops, at the sides of which ejections towards the corona or arcs receding to the disk could be observed. Radio burst of type IV and II occurred in the explosive phase of the flare, as well as a hard X-ray emission burst within the same interval in which bright flare loops were generated at the very beginning, and when partlcle acceleration apparently occurred. The fast particles were not recorded on the Earth due to its unfavourable position relative to their source and trajectory, but after 17:00 UT the X-ray photometer aboard the Prognoz-8 satellite registered a large number of unresolved fast particles (see Fig. 3). The studied phenomenon belongs to the interval of the Solar Maximum Year (Aug. 1979 - Feb. 1981).
Rights:
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4. Magnetic field gradients and X-ray emissions of solar activity centra

Creator:
Valníček, B. and Šeršeň, M.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
heliophysics and X-rays
Language:
Czech
Description:
The intensity and complexity of X-ray bursts generally is dependent by horizontal gradients of photospherical magnetic field on the line of polarity inversion. It is documented that lower gradient of H is giving (for weak X-rays) generally gradual drops of fiux, in comparison with higher one. The maxiinal value of X-radiation is proportional to the value of H-gradient on the line of polarity inversion. Generally, this gradient is determining the steepness of the front of the X-burst and of the share of hard X-rays component. This can be explained by difference in the quantity and energy of accelerated electrons in kernels of the flare.
Rights:
http://creativecommons.org/publicdomain/mark/1.0/ and policy:public

5. New type of interference-polarizattion filter and its application in astronomy

Creator:
Valníček, B.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
astronomy, interference-polarization filters, and Šolc type filters
Language:
Czech
Description:
The present study deals with the properties oi the Šolc type monochromatic interference-polarization filters and the possibilities of their use for solar observations. In the first part the characteristics of the Šolc filter in distinction to those of the Lyot filter are mentioned. Then, the features of some of the working Šolc type filters are studied and the results obtained by means of them are compared with the theoretically assessed values. In particular the following properties háve been investigated: the half-widths of the individual filters and their dependence on the wavelength, the spacing of the principal maxima of the filters and their dependence on the wavelength, the spacing and intensity of the first secondary maxima, the permissible convergence of the beam of rays entering into the filter, the dependence of the position of the maxima on the inclination of the filter to the optic axis, the dependence of the position of the maxima on temperature and the transmission of the filter. The obtained results are presented in table and diagrams. Summarilly it can be said that the Šolc type filters offer an advantageous research tool in cases, where their considerable intensity of the secondary maxima and their high sensitivity to the convergence of the beams is not a handicap, in other words, that they are very well suited for observations of prominences in a coronograph, where their high transmission at a relatively large half-width will be appreciated. On the other hand, in cases where a smáli half-width is required, that is, first of all in observations of the chromosphere, the use of the filters has some limitations. In the concluding part some actual cases of application of the mentioned filters for observations of prominences and of the chromosphere are demonstrated.
Rights:
http://creativecommons.org/publicdomain/mark/1.0/ and policy:public

6. Photoelectric photometry of the comet Arend-Roland 1956h

Creator:
Valníček, B. and Růžičková, B.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
photoelectric photometry, chromospherical flares, and comets
Language:
Czech
Description:
Photoelectric measurements of light-changes in the comet Arend-Roland were made from April 22nd to May 6th 1957. From the measurements the absolute magnitude of the comet for the spectral range of 4000 A, m0 = 6.73. n = 3.48 was established. The curve of the light-changes was compared with the incidence of chromospherical flares in this period. Traces of a possible connection of the alterations in the comet´s brightness with changes in the solar activity were recorded.
Rights:
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7. Prognoz data - Part IV: Solar X-ray flux in the 4-8 keV band during the period July 1, 1983 - January 13, 1984

Creator:
Valníček, B., Fárník, F., Sudová, J., Komárek, B., Likin, O., and Pisarenko, N.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
Prognoz satellite and solar X-ray photometer
Language:
Czech
Description:
Introduction: In July 1983 the Prognoz 9 satellite was launched with the fifth Czechoslovak solar X-ray photometer of the Prognoz type (RF - 2P) onboard. This publication represents a brief description of the instrument ad survey plots of obtained data. Similar plots have been published in the three previous books containing data from the Prognoz 5, 6, 7 and 8 experiments. The Prognoz 8 satellite was launched on July 1, 1983 into the orbit of apogee of 720 000 km and perigee of 380 km, inclination of 65° and orbital period of about 641 hours. This photometer was in operation till January 15, 1984. and Kontakt: František Fárník
Rights:
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8. Search for optical flashes from Gamma-ray burst sources

Creator:
Hudec, R., Borovička, J., Peřestý, R., and Valníček, B.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
astronomy, gamma-ray bursters, and optical flashes
Language:
Czech
Description:
Preliminary results of an extended program of examination of the Ondřejov and Sonneberg plate collectons for possible optical counterparts to gamma-ray bursters are presented. One optical image was found on 3 different plates at the same position suggesting it may be related to gamma-ray burster 1979 March 25 B. Results of both archival and time-correlated searches are discussed for GRBS as well as for the Perseus Flasher.
Rights:
http://creativecommons.org/publicdomain/mark/1.0/ and policy:public

9. The paraboloid-paraboloid microscopic optical X-ray system: First experience 1. production and tests

Creator:
Hudec, R., Valníček, B., Peřestý, R., Šolc, I., Lochman, J., Svátek, L., Landa, V., V., Zhitnik, I., Krutov, V., Burkert, W., Bräuninger, H., and Predehl, P.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
optical X-ray system, paraboloid-paraboloid system, and measurements
Language:
Czech
Description:
The microscopic optical X-ray system of the paraboloid-paraboloid type is based on a galvanoplastic replics. The study describes the production procedure and the first tests in optical and X-ray light. Briefly discussed are the results obtained as well as the possibility of using mirrors of this type for mappng X-ray plasma during nuclear fusion.
Rights:
http://creativecommons.org/publicdomain/mark/1.0/ and policy:public