Research Center for Astronomy and Earth science

Sopron, Hungary

Research Center for Astronomy and Earth science

Sopron, Hungary
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Kereszturi A.,Research Center for Astronomy and Earth science | Noack L.,Royal Observatory of Belgium
Origins of Life and Evolution of Biospheres | Year: 2016

In this work various factors on the habitability were considered, focusing on conditions irrespective of the central star’s radiation, to see the role of specific planetary body related effects. These so called planetary factors were evaluated to identify those trans-domain issues where important information is missing but good chance exit to be filled by new knowledge that might be gained in the next decade(s). Among these strategic knowledge gaps, specific issues are listed, like occurrence of radioactive nucleides in star forming regions, models to estimate the existence of subsurface liquid water from bulk parameters plus evolutionary context of the given system, estimation on the existence of redox gradient depending on the environment type etc. These issues require substantial improvement of modelling and statistical handling of various cases, as “planetary environment types”. Based on our current knowledge it is probable that subsurface habitability is at least as frequent, or more frequent than surface habitability. Unfortunately it is more difficult from observations to infer conditions for subsurface habitability, but specific argumentation might help with indirect ways, which might result in new methods to approach habitability in general. © 2016 Springer Science+Business Media Dordrecht


Murphy S.J.,University of Central Lancashire | Murphy S.J.,University of Porto | Pigulski A.,Wrocław University | Kurtz D.W.,University of Central Lancashire | And 15 more authors.
Monthly Notices of the Royal Astronomical Society | Year: 2013

The candidate SX Phe star KIC 11754974 shows a remarkably high number of combination frequencies in the Fourier amplitude spectrum: 123 of the 166 frequencies in our multifrequency fit are linear combinations of independent modes. Predictable patterns in frequency spacings are seen in the Fourier transform of the light curve. We present an analysis of 180 d of short-cadence Kepler photometry and of new spectroscopic data for this evolved, late A-type star. We infer from the 1150-d, long-cadence light curve, and in two different ways, that our target is the primary of a 343-d, non-eclipsing binary system. According to both methods, the mass function is similar, f (M) = 0.0207 ± 0.0003M⊙. The observed pulsations are modelled extensively, using separate, state-of-the-art, time-dependent convection (TDC) and rotating models. The models match the observed temperature and low metallicity, finding a mass of 1.50-1.56M⊙. The models suggest that the whole star is metal poor, and that the low metallicity is not just a surface abundance peculiarity. This is the best frequency analysis of an SX Phe star, and the only Kepler δ Sct star to be modelled with both TDC and rotating models. © 2013 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society.


Kudrin A.V.,Nizhny Novgorod State Technical University | Shkokova N.M.,Nizhny Novgorod State Technical University | Ferencz O.E.,Research Center for Astronomy and Earth science | Zaboronkova T.M.,Nizhny Novgorod State Technical University
Physics of Plasmas | Year: 2014

Pulsed radiation from a loop antenna located in a cylindrical duct with enhanced plasma density is studied. The radiated energy and its distribution over the spatial and frequency spectra of the excited waves are derived and analyzed as functions of the antenna and duct parameters. Numerical results referring to the case where the frequency spectrum of the antenna current is concentrated in the whistler range are reported. It is shown that under ionospheric conditions, the presence of an artificial duct with enhanced density can lead to a significant increase in the energy radiated from a pulsed loop antenna compared with the case where the same source is immersed in the surrounding uniform magnetoplasma. The results obtained can be useful in planning active ionospheric experiments with pulsed electromagnetic sources operated in the presence of artificial field-aligned plasma density irregularities that are capable of guiding whistler waves. © 2014 AIP Publishing LLC.


Pal A.,Research Center for Astronomy and Earth science | Pal A.,Eötvös Loránd University | Meszaros L.,Research Center for Astronomy and Earth science | Meszaros L.,Eötvös Loránd University | And 10 more authors.
Astronomische Nachrichten | Year: 2013

In this paper we briefly summarize the design concepts of the Fly's Eye Camera System, a proposed high resolution allsky monitoring device which intends to perform high cadence time domain astronomy in multiple optical passbands while still accomplish a high étendue. Fundings have already been accepted by the Hungarian Academy of Sciences in order to design and build a Fly's Eye device unit. Beyond the technical details and the actual scientific goals, this paper also discusses the possibilities and yields of a network operation involving ~10 sites distributed geographically in a nearly homogeneous manner. Currently, we expect to finalize the mount assembly - that performs the sidereal tracking during the exposures - until the end of 2012 and to have a working prototype with a reduced number of individual cameras sometimes in the spring or summer of 2013. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Szalai S.,Research Center for Astronomy and Earth Science | Novak A.,Research Center for Astronomy and Earth Science | Szokoli K.,Research Center for Astronomy and Earth Science
Near Surface Geoscience 2013 | Year: 2013

The issue of depth of investigation has always been a basic problem in geophysical studies. Nowadays, as more and more research should be carried out in built-up areas where space is limited, it became even more important. Since we think that the depth of investigation is basically determined by the detectability of small-size inhomogeneities, the so-called depth of detectability (DD) values, this parameter is investigated in this presentation for the 2D ERT. In the case of the studied prism and dyke models the not-yet investigated g11n arrays gave systematically higher DD values than the pole-dipole and dipole axial arrays which were the best conventional arrays from this point of view. The difference can be significant, up-to 2-2.5-fold in comparison even with these arrays. This makes possible to obtain useful information even where the measuring area is limited, eg. in settlements, in less time and from greater depth. Moreover, due to the imaging properties of arrays having larger DD values are generally better it is easily possible that these arrays have also better imaging properties than those of the traditional arrays.


Bondar I.,Research Center for Astronomy and Earth science | Engdahl E.R.,University of Colorado at Boulder | Villasenor A.,CSIC - Institute of Earth Sciences Jaume Almera | Harris J.,Research Center for Astronomy and Earth science | Storchak D.,Research Center for Astronomy and Earth science
Physics of the Earth and Planetary Interiors | Year: 2015

We present the final results of a two-year project sponsored by the Global Earthquake Model (GEM) Foundation. The ISC-GEM global catalogue consists of some 19 thousand instrumentally recorded, moderate to large earthquakes, spanning 110. years of seismicity. We relocated all events in the catalogue using a two-tier approach. The EHB location methodology (Engdahl et al., 1998) was applied first to obtain improved hypocentres with special focus on the depth determination. The locations were further refined in the next step by fixing the depths to those from the EHB analysis and applying the new International Seismological Centre (ISC) location algorithm (Bondár and Storchak, 2011) that reduces location bias by accounting for correlated travel-time prediction error structure. To facilitate the relocation effort, some one million seismic P and S wave arrival-time data were added to the ISC database for the period between 1904 and 1970, either from original station bulletins in the ISC archive or by digitizing the scanned images of the International Seismological Summary (ISS) bulletin (Villaseñor and Engdahl, 2005, 2007). Although no substantial amount of new phase data were acquired for the modern period (1964-2009), the number of phases used in the location has still increased by three millions, owing to fact that both the EHB and ISC locators use most well-recorded ak135 (Kennett et al., 1995) phases in the location.We show that the relocation effort yielded substantially improved locations, especially in the first half of the 20th century; we demonstrate significant improvements in focal depth estimates in subduction zones and other seismically active regions; and we show that the ISC-GEM catalogue provides an improved view of 110. years of global seismicity of the Earth. The ISC-GEM Global Instrumental Earthquake Catalogue represents the final product of one of the ten global components in the GEM program, and is available to researchers at the ISC (. www.isc.ac.uk) website. © 2014 Elsevier B.V.


Kereszturi A.,Research Center for Astronomy and Earth science | Bradak B.,Research Center for Astronomy and Earth science | Bradak B.,Kobe University | Chatzitheodoridis E.,National Technical University of Athens | Ujvari G.,Research Center for Astronomy and Earth science
Origins of Life and Evolution of Biospheres | Year: 2016

Great advances are expected during the analysis of drilled material acquired from 2 m depth by ExoMars rover, supported by the comparison to local context, and the joint use of different instruments. Textural information might be less detailed relatively to what is usually obtained at outcrops during classical geological field work on the Earth, partly because of the lack of optical imaging of the borehole wall and also because the collected samples are crushed. However sub-mm scale layering and some other sedimentary features might be identified in the borehole wall observations, or in the collected sample prior to crushing, and also at nearby outcrops. The candidate landing sites provide different targets and focus for research: Oxia Planum requires analysis of phyllosilicates and OH content, at Mawrth Vallis the layering of various phyllosilicates and the role of shallow-subsurface leaching should be emphasized. At Aram Dorsum the particle size and fluvial sedimentary features will be interesting. Hydrated perchlorates and sulphates are ideal targets possibly at every landing sites because of OH retention, especially if they are mixed with smectites, thus could point to even ancient wet periods. Extensive use of information from the infrared wall scanning will be complemented for geological context by orbital and rover imaging of nearby outcrops. Information from the context is especially useful to infer the possible action of past H2O. Separation of the ice and liquid water effects will be supported by cation abundance and sedimentary context. Shape of grains also helps here, and composition of transported grains points to the weathering potential of the environment in general. The work on Mars during the drilling and sample analysis will provide brand new experience and knowledge for future missions. © 2016 Springer Science+Business Media Dordrecht


PubMed | National Technical University of Athens and Research Center for Astronomy and Earth science
Type: Journal Article | Journal: Origins of life and evolution of the biosphere : the journal of the International Society for the Study of the Origin of Life | Year: 2016

We surveyed the Martian surface in order to identify possible source craters of the nakhlite Martian meteorites. We investigated rayed craters that are assumed to be younger than 11Ma, on lava surfaces with a solidification age around 1.2Ga. An area of 17.3 million km


PubMed | National Technical University of Athens and Research Center for Astronomy and Earth science
Type: Journal Article | Journal: Origins of life and evolution of the biosphere : the journal of the International Society for the Study of the Origin of Life | Year: 2016

Great advances are expected during the analysis of drilled material acquired from 2m depth by ExoMars rover, supported by the comparison to local context, and the joint use of different instruments. Textural information might be less detailed relatively to what is usually obtained at outcrops during classical geological field work on the Earth, partly because of the lack of optical imaging of the borehole wall and also because the collected samples are crushed. However sub-mm scale layering and some other sedimentary features might be identified in the borehole wall observations, or in the collected sample prior to crushing, and also at nearby outcrops. The candidate landing sites provide different targets and focus for research: Oxia Planum requires analysis of phyllosilicates and OH content, at Mawrth Vallis the layering of various phyllosilicates and the role of shallow-subsurface leaching should be emphasized. At Aram Dorsum the particle size and fluvial sedimentary features will be interesting. Hydrated perchlorates and sulphates are ideal targets possibly at every landing sites because of OH retention, especially if they are mixed with smectites, thus could point to even ancient wet periods. Extensive use of information from the infrared wall scanning will be complemented for geological context by orbital and rover imaging of nearby outcrops. Information from the context is especially useful to infer the possible action of past H


Kereszturi A.,Research Center for Astronomy and Earth science | Chatzitheodoridis E.,National Technical University of Athens
Origins of Life and Evolution of Biospheres | Year: 2016

We surveyed the Martian surface in order to identify possible source craters of the nakhlite Martian meteorites. We investigated rayed craters that are assumed to be younger than 11 Ma, on lava surfaces with a solidification age around 1.2 Ga. An area of 17.3 million km2 Amazonian lava plains was surveyed and 53 rayed craters were identified. Although most of them are smaller than the threshold limit that is estimated as minimum of launching fragments to possible Earth crossing trajectories, their observed size frequency distribution agrees with the expected areal density from cratering models characteristic for craters that are less than few tens of Ma old. We identified 6 craters larger than 3 km diameter constituting the potentially best source craters for nakhlites. These larger candidates are located mostly on a smooth lava surface, and in some cases, on the earlier fluvial-like channels. In three cases they are associated with fluidized ejecta lobes and rays – although the rays are faint in these craters, thus might be older than the other craters with more obvious rays. More work is therefore required to accurately estimate ages based on ray system for this purpose. A more detailed search should further link remote sensing Martian data with the in-situ laboratory analyses of Martian meteorites, especially in case of high altitude, steep terrains, where the crater rays seems to rarely survive several Ma. © 2016 Springer Science+Business Media Dordrecht

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