Ne (217)
Počet nalezených dokumentů:
217
Publikováno od
do
Automation of processing and photometric data analysis for transiting exoplanets observed with ESO NIR instrument HAWK-I
Blažek, M.; Kabáth, Petr; Klocová, Tereza; Skarka, Marek
2018 - anglický
Nowadays, when amount of data still increases, it is necessary to automatise their processing. State-of-the-art instruments are capable to produce even tens of thousands of images during a single night. One of them is HAWK-I that is a part of Very Large Telescope of European Southern Observatory. This instrument works in near-infrared band. In my Master thesis, I dealt with developing a pipeline to process data obtained by the instrument. It is written in Python programming language using commands of IRAF astronomical software and it is developed directly for “Fast Photometry Mode” of HAWK-I. In this mode, a large number of data has been obtained during secondary eclipses of exoplanets by their host star. The pipeline was tested by a data set from sorting of the images to making a light curve. The data of WASP-18 system contained almost 40 000 images observed by using a filter centered at 2.09 μm wavelength and there is a plan to process other data sets. A goal of processing of WASP-18 and the other data sets is consecutive analysis of exoplanetary atmospheres of the observed systems.
Klíčová slova:
observational methods; photometric techniques; planetary systems
Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
Automation of processing and photometric data analysis for transiting exoplanets observed with ESO NIR instrument HAWK-I
Nowadays, when amount of data still increases, it is necessary to automatise their processing. State-of-the-art instruments are capable to produce even tens of thousands of images during a single ...
Z CVn - Still mysterious
Skarka, Marek; Liška, J.; Dřevěný, R.; Sódor, A.; Kolenberg, B.
2018 - anglický
We comment on short- and long-term pulsation period variations of Z CVn, a classical RR Lyrae star with the Blazhko effect. Z CVn shows cyclic-like O-C diagram that can be interpreted as a consequence of binarity throught the light travel time effect. We show that this hypothesis is false and that the observed long-term period variations must be caused by some effect that is intrinsic to the star. We also show that the Blazhko period is not simply anti-correlated with the long-term period variations as was suggested by previous authors.
Klíčová slova:
long-term pulsation; short-term pulsation; Blazhko effect
Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
Z CVn - Still mysterious
We comment on short- and long-term pulsation period variations of Z CVn, a classical RR Lyrae star with the Blazhko effect. Z CVn shows cyclic-like O-C diagram that can be interpreted as a consequence ...
Flows along arch filaments observed in the GRIS `very fast spectroscopic mode'
Gonzalez Manrique, S. J.; Denker, C.; Kuckein, C.; Pastor Yabar, A.; Collados Vera, M.; Verma, M.; Balthasar, H.; Diercke, A.; Fischer, C.E.; Gömöry, P.; Bello González, N.; Schlichenmaier, R.; Cubas Armas, M.; Berkefeld, T.; Feller, A.; Hoch, S.; Hofmann, A.; Lagg, A.; Nicklas, H.; Orozco Suárez, D.; Schmidt, D.; Schmid, W.; Sigwarth, M.; Sobotka, Michal; Solanki, S.K.; Soltau, D.; Staude, J.; Strassmeier, K.G.; Volkmer, R.; von der Lühe, O.; Waldmann, T.A.
2017 - anglický
A new generation of solar instruments provides improved spectral, spatial, and temporal resolution, thus facilitating a better understanding of dynamic processes on the Sun. High-resolution observations often reveal multiple-component spectral line profiles, which provides information about the chromospheric velocity and magnetic fine structure. We observed an emerging flux region, including two small pores and an arch filament system, on 2015 April 17 with the "very fast spectroscopic mode" of the GREGOR Infrared Spectrograph (GRIS) situated at the 1.5-meter GREGOR solar telescope at Observatorio del Teide, Tenerife, Spain. We discuss this method of obtaining fast (one per minute) spectral scans of the solar surface and its potential to follow dynamic processes on the Sun. We demonstrate the performance of the "very fast spectroscopic mode" by tracking chromospheric high-velocity features in the arch filament system.
Klíčová slova:
Sun; chromosphere; photosphere
Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
Flows along arch filaments observed in the GRIS `very fast spectroscopic mode'
A new generation of solar instruments provides improved spectral, spatial, and temporal resolution, thus facilitating a better understanding of dynamic processes on the Sun. High-resolution ...
Cristannus de Prachaticz’s Treatises on the Astrolabe
Hadrava, Petr; Hadravová, Alena
2017 - anglický
The authors' computer methods of collation and statistical treatment of variant readings are summarized and illustrated on the example of the critical edition of the treatises on Composition and Use of the Astrolabe written by the 15th-century Czech scholar Cristannus de Prachaticz.\n
Klíčová slova:
history of astronomy; computer-asisted critical editions; digital stematology
Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
Cristannus de Prachaticz’s Treatises on the Astrolabe
The authors' computer methods of collation and statistical treatment of variant readings are summarized and illustrated on the example of the critical edition of the treatises on Composition and Use ...
Study of Cataclysmic Variables with the Satellites LOFT and Gaia
Hudec, René; Šimon, Vojtěch
2015 - anglický
The goal of this paper is to discuss the capabilities of ESA satellite missions Gaia (already in space) and LOFT\n(considered for the ESA M4 slot) for investigation of cataclysmic variables (CVs). Both Gaia and LOFT\ncan contribute to study of CVs and related objects. Spectrophotometry and low dispersion spectroscopy are the most important for CV analyses with the observations of Gaia. We present the possible strategies for investigation of CVs in the sampled photometric\nand spectroscopic data provided by Gaia. E.g. statistical properties of the long-term activity of various types of CVs can be determined from them. LOFTcan be a promising satellite to provide a sensitive X-ray monitor which will enable to investigate the little studied long-term activity of various types of CVs (especially the magnetic ones) in the X-ray band.
Klíčová slova:
catalysmic variables; dwarf novae -; intermediate polar
Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
Study of Cataclysmic Variables with the Satellites LOFT and Gaia
The goal of this paper is to discuss the capabilities of ESA satellite missions Gaia (already in space) and LOFT\n(considered for the ESA M4 slot) for investigation of cataclysmic variables (CVs). ...
Activity of the Polar AM Her (RX J1816.2+4952): A Short Review
Šimon, Vojtěch; Henden, A.
2015 - anglický
We show that AM Her displays the transitions between the high and low states with an intermittently existing dominant\ncycle with length between 400 and 800 days. Moreover, these transitions accumulate in clusters, which produces an\nadditional long cycle after smoothing; a single isolated short episode of the low state does not suggest a break of this cycle. The seasons of existence of the cycle can be controlled by the lifetime of the active regions (e.g. prominences, spots) on the donor. In some high-state episodes, a higher luminosity of the bremsstrahlung emission is not accompanied by a higher optical (cyclotron+stream) emission. Part of the bremsstrahlung emission can be buried in some episodes. Changes of\nthe structure of the accretion region(s) are necessary to explain the variations of the optical and X-ray activity in the\nhigh-state episodes of AM Her.
Klíčová slova:
catalysmic variables; polars; emission mechanism
Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
Activity of the Polar AM Her (RX J1816.2+4952): A Short Review
We show that AM Her displays the transitions between the high and low states with an intermittently existing dominant\ncycle with length between 400 and 800 days. Moreover, these transitions ...
GLORIA and Study of Cataclysmic Variables
Šimon, Vojtěch; Hudec, René
2015 - anglický
We report here on the ongoing EU FP7 Project GLORIA (GLObal Robotic-telescopes Intelligent Array) with emphasis on possibility of investigation of cataclysmic variables by users. GLORIA will enable the rst free and open-access network of robotic telescopes in the world. We show several examples of the not often used topics (but suitable for GLORIA) for the studies of activity of cataclysmic variables, e.g. search for outbursts in intermediate polars and the uctuations of/nbrightness in their quiescence, and investigation of the optical counterparts of supersoft X-ray sources.
Klíčová slova:
catalysmic variables; spectroscopy; low-dispersion spectra
Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
GLORIA and Study of Cataclysmic Variables
We report here on the ongoing EU FP7 Project GLORIA (GLObal Robotic-telescopes Intelligent Array) with emphasis on possibility of investigation of cataclysmic variables by users. GLORIA will enable ...
Equilibria of charged dust tori in a dipole magnetic field: hydrodynamic approach
Slaný, P.; Kovář, J.; Stuchlík, Z.; Karas, Vladimír
2014 - anglický
The authors present Newtonian model of non-conductive charge perfect fluid tori orbiting in combined spherical gravitational and dipolar magnetic fields, focusing on stationary, axisymmetric toroidal structures.
Klíčová slova:
dust tori; electric charge; magnetic field
Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
Equilibria of charged dust tori in a dipole magnetic field: hydrodynamic approach
The authors present Newtonian model of non-conductive charge perfect fluid tori orbiting in combined spherical gravitational and dipolar magnetic fields, focusing on stationary, axisymmetric toroidal ...
Polarization vector transport in Kerr geometry
Bursa, Michal; Horák, Jiří; Karssen, G.
2014 - anglický
In this paper the authors proved a set of practical formulae that are helpful in calculating the orientation of polarization vectors that are parallel transported from a region of strong gravitational field of a Kerr black hole to a distant observer.
Klíčová slova:
polarization; black hole; electromagnetic radiation
Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
Polarization vector transport in Kerr geometry
In this paper the authors proved a set of practical formulae that are helpful in calculating the orientation of polarization vectors that are parallel transported from a region of strong gravitational ...
An Introduction to relativistic magnetohydrodynamics. II. Case of stationary electro-vacuum fields around black holes
Karas, Vladimír
2014 - anglický
The lecture on electrodynamical effects near black holes. The author summarize the basic equations of relativistic electrodynamics in terms of spin-coefficien formalism.
Klíčová slova:
black holes; electromagnetic fields; relativity
Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
An Introduction to relativistic magnetohydrodynamics. II. Case of stationary electro-vacuum fields around black holes
The lecture on electrodynamical effects near black holes. The author summarize the basic equations of relativistic electrodynamics in terms of spin-coefficien formalism.
NUŠL poskytuje centrální přístup k informacím o šedé literatuře vznikající v ČR v oblastech vědy, výzkumu a vzdělávání. Více informací o šedé literatuře a NUŠL najdete na webu služby.
Vaše náměty a připomínky posílejte na email nusl@techlib.cz
Provozovatel
Zahraniční báze