Number of results to display per page
Search Results
382. A search of tidal interaction in the binary system λ And
- Creator:
- Głębocki, R., Bielicz, E., Pastuszka, Z., and Sikorski, J.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- astrophysics, tidal interaction, and binary system λ And
- Language:
- Czech
- Description:
- 31 UV spectra obtained with tne LWR camera of the lUE satellite in the period 1978-83 were analysed. Changes of Mg II h and k emissions are evident but there is no evident correlation between emission intensity of Mg II and orbital or photometric phase. Using three various methods of analysis of possible periodicity in variation of Mg II h and k emission intensities we have found reál chanes in h + k fluxes with period equal to the half of the orbital one, 0.5 Porb = 10.2606. We interpret this effect as evidence of direct influence of tidal inxeraction of secondary component on the chromospheric structure of the primary. Evident minimum of the Mg II h and k intensity is observed when the tides are on the line of sight and maximum when both tidal bulges are visible. Difference between maximum and minimum of total flux of k line is equal to about 20%, while the shape of the profile is practically unchanged.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
383. A simple calibration link for a laser radar
- Creator:
- Neubert, R. and Grunwaldt, L.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- simple calibration link, laser radar, and satellite laser stations
- Language:
- Czech
- Description:
- Most satellite laser stations have used extermal terrestrial targets at distances from several hundred metres to kilometres for the determination of the calibration constant. The disadvantage of this method is the incomplete overlap of the transmitter and receiver angular fields and the necessity to monitor accurately the optical distance of the remote target. At Potsdam station, one year ago we introduced a very simple calibration link based on dual diffuse scattering, which can be easily attached in front of any laser radar. No optical components other than diffuse reflectors are used. The inherent attenuation is about 10^13, so that a 1000 : 1 additional filter is sufficient to reach the single photoelectron level. The method has been used for routing operations during the MERIT campaign and for investigating some error sources as well.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
384. A simple method to estimate large fixed effects models applied to wage determinants and matching
- Creator:
- Mittag, Nikolas
- Publisher:
- CERGE-EI
- Format:
- electronic, svazek, and 55 stran
- Type:
- model:monograph and TEXT
- Subject:
- Ekonomie, trh práce, mzdy, modelování a simulace, labor market, wages, modeling and simulation, 331.5, 331.2, 519.86/.87, (048.8), 4, and 33
- Language:
- English and Czech
- Description:
- Nikolas Mittag., Obsahuje bibliografii a bibliografické odkazy, and Český a anglický abstrakt
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
385. A solar radio telescope for the wavelengths of 56 and 130 cm
- Creator:
- Budějický, J.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- Ondřejov Observatory, radio telescope, and measurement accuracy
- Language:
- Czech
- Description:
- In the paper is described the construction of the radio telescope for the wavelengths of 56 and 130 cm which has been used on the observatory of the Astronomical Institute of the ČSAV at Ondřejov for radio observations of the sun. Prevailing part of the work is devoted to the receiving equipment for the wavelength of 56 crn, which whole was built in own laboratories and which has been for 3 years in everyday operation. The author explains the determination of the fundamental parameters of the equipment and describes the means necessary to reach them. The design proposal and the realization of the receiver for the wavelength of 56 cm together with a high-stability d. c. amplifier and the design and realization of the calibrating arrangements including diode noisegenerator are described. Further the author considers to the details the influence of different quantities on the measurement accuracy and on the estimation of the resulting power flux density in the antenna apertuře with this instrument. Finally, a servomechanism performing automatic transformation of equatorial to azimuthal coordinates is described. In the next part the 130 cm - equipment is briefly mentioned. This equipment was of substantial part built outside the Institute. The both receiving apparatus use a common mirror of 7‘5m diameter having in its focus two primary feeds with polarizations perpendicular to each other.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
386. A spatial distribution of the young populations of various age groups in the Sagittarius-Carina arm
- Creator:
- Avedisová, V. S.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- space research, spiral pattern parameters, and Sagittarius-Carina arm
- Language:
- Czech
- Description:
- The spatial distribution of the young objects of varioue age groups - HII regions and open clusters - in the Saglttarius-Carina arm (SC arm) at 1 « 280°- 25° ie Inyestlgated. Both transverse and longitudinal age gradients have been found in the arm, Two giant star formation complexes with the size of about 1 kpc at 1 = 285°-300° at 1 = 340°-20° are existed, Each of them contains several giant HII regions, a number of glant moleoular clouds (GMCa) and some extremely young clusters, Between these complexes we have found an elder one of the same aime.This complex contains 24 (3-6)»10^7 years old clusters and a small number of faint HII regions. Assuming that it is a remnant of a giant star formation complex the upper limit of lifetimes for such complexes and GMCs is (3-6)•10^7 years, The estimations of spiral pattem parameters are made.The value of the pitch-angle is 21°+3°. The value of spiral pattem velocity, -26.8+2.2 km/s«kpc, leads us to conclusion that the Sun is near the oorrotation radius of the Galaxy. The star formation efficiency in these complexes is discussed.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
387. A spectrometric study of Ap-stars
- Creator:
- Vilhu, O. and Tuominen, I.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- astrophysics, spectrometry, and Ap-stars
- Language:
- Czech
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
388. A study of activity in interacting sunspot groups
- Creator:
- Schmieder, B., van Driel-Gesztelyi, L., and Hénoux, J.-C.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- heliophysics and sunspot groups
- Language:
- Czech
- Description:
- Two interacting active regions of different ages have been studied over two days using white light and Hα observations as well as magnetograma. Different series of homologous flares and the formation of a filament in tbe region were analysed and an interpretation of these events is proposed.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
389. A third medieval bridge on Lake Lednica, Greater Poland
- Creator:
- Pydyn, Andrzej and Popek, Mateusz
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- bridge, Middle Ages, Lake Lednica, underwater archaeology, most, středověk, Lednické jezero, and podvodní archeologie
- Language:
- Czech
- Description:
- Lake Lednica, Greater Poland, is one of Poland’s most important and longest-studied underwater archaeological sites. The residential centre established on an island was one of the central points in the state of the first Piasts. Previous research located two bridges to the island and discovered the largest collection of early medieval military objects in Central Europe in the lake. In the 2017 season, a third bridge was discovered on Lake Lednica leading to the small island called Ledniczka on which the layers of an early medieval settlement and clear remnants of a motte-type medieval structure are found. Three seasons of research on relics of the crossing suggest that it may have functioned in two periods: in the tenth century and at the turn of the fourteenth century. During the research, a number of military items, pottery, objects made of organic materials and fishing tools were found. and Lednické jezero ve Velkopolsku patří k nejdůležitějším a nejdéle studovaným lokalitám podvodní archeologie ve střední Evropě. Rezidenční centrum zřízené na zdejším Lednickém ostrově bylo jedním z hlavních míst prvních Piastovců. Předchozí výzkum odhalil dva mosty spojující ostrov s pevninou a největší soubor militárií ze dna středoevropského jezera. V roce 2017 byl identifikován další most, tentokrát zpřístupňující ostrůvek zvaný Ledniczka. Další výzkum ukázal, že most pravděpodobně fungoval ve dvou periodách: v 10. století a na přelomu 13. a 14. století. Přinesl také početný soubor militárií, keramiky, rybářského náčiní a výrobků z organických materiálů. Na ostrůvku byly dokumentovány raně středověké situace a opevnění typu motte.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
390. A trapezium born in a bipolar nebula
- Creator:
- Neckel, Th., Staude, H. J., and Meisenheimer, K.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- observations, bipolar nebulae, and trapezium
- Language:
- Czech
- Description:
- We present various observations of the bipolar nebula No. 14 from the list of Neckel and Staude (1984): CCD images at 7 different wavelengths, spectroscopy at intermediate resolution between 4800 A and 9500 A, and CCD stellar polarimetry. The centra! star turns out to be a "Trapezium" consisting of four stars of spectral types between B0.5 and A5. The nebular spectrum is that of a low excited HII region, but in addition it exhibits a strong Ol 8446 line excited by Lyman β fluorescence. This requires a very high optical depth in Hα γ ≥ 1000) in the emitting region, which has been spatially resolved in NS 14. The stellar polarimetry, combined with the surface polarimetry of Scarrott et al. (1986), indicates that the polarization in the nebula can be explained by pure scattering alone.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public