Search Publications
Neural network based identification of energy conversion regions and bursty bulk flows in Cluster data
Marghitu, Octav; Constantinescu, Vlad
Neural networks (NN) provide a powerful pattern recognition tool, that can be used to search large amounts of data for certain types of 'events'. Our specific goal is to make use of NN in order to identify events in time series, in particular energy conversion regions (ECRs) and bursty bulk flows (BBFs) observed by the Cluster spacecraft in the ma…
HD 121620: A Previously Unreported Variable Star with Unusual Properties
Axelsen, R. A.
During a study of the delta Scuti star V1393 Centauri by digital single lens reflex photometry, it was found that two of the chosen comparison stars were variable. This paper reports the subsequent investigation of one of them, HD 121620, which revealed irregular light variations of 0.8 magnitude in V within a time frame of approximately 24 hours.…
Pinnacles on the surface of the comet 67P/Churyumov-Gerasimenko: regional distribution and morphology
Keller, H. U.; Hviid, S. F.; Mall, U. +3 more
Pinnacles are local topographic promontories of different shapes considered to be formed due to uneven surface erosion. In the case of comets, areal changes in the degree of erosion could be related to inhomogeneities of the nucleus. However, the amount of the solar radiation and the thermal gradient is different across the orbit for geomorphologi…
Analysis of HAT-P-23 b, Qatar-1 b, WASP-2 b, and WASP-33 b with an Optimized EXOplanet Transit Interpretation Code (Abstract)
Nair, S.; Varghese, J.; Tock, K. +1 more
(Abstract only) The ability for citizen scientists to analyze image data and search for exoplanets using images from small telescopes has the potential to greatly accelerate the search for exoplanets. Recent work on the Exoplanet Transit Interpretation Code (EXOTIC) enables the generation of high-quality light curves of exoplanet transits given su…
Simple model of the wave pattern in the atmosphere of a slow rotating planet due to surface irregularities
Vigh, Carlos; Cirilo-Lombardo, Diego; Mayochi, Mariano +1 more
Recent observations show a persistent pattern on Venus surface, interpreted as a stationary wave due to the interaction of the prevailing winds with the orography of the planet. In this work we use an idealized model of the phenomenon that allows for a fully analytical solution applied to a slow rotating planet with idealized obstacles. We use Ven…
On possibility using photometry of Landolt fields for determination of stellar parameters and interstellar reddening
Pakhomov, Yu. V.; Stepina, Yu. A.
The paper analyzes the possibility of determination of stellar parameters and interstellar reddening based on UBVRIJHK photometry of secondary standards of the Landolt field S98. It is shown that the accuracy of photometric measurements should be 0.010 - 0.015 m or better and, at least 0.02 m , if a measured parallax is available.
Spectroscopy of B and Be Stars in the Young Open Star Cluster NGC 581 (M 103)
Tarasov, A. E.
Based on moderate-resolution spectra in the range 4200-5200 Å, we have studied B and Be stars in the young open star cluster NGC 581. The temperatures of the program stars have been derived by the differential method with the choice of simple spectroscopic parameters for a number of lines and their comparison with the analogous parameters of a lar…
Mineralogical Mapping Using Chandrayaan-1 Hyperspectral (HySI) Data from the South Pole Region
Sayyad, S. B.; Mohammed Zeeshan, R.
The space weathering effect acts as barrier for accurately assessing the surface mineralogy and compositional analysis. It can be addressed by radiative transfer model that best explains the space weathering effect on remotely sensed spectra.
Unveiling the mineralogical composition of lunar farside mare basalts
Flahaut, Jessica; Bott, Nicolas; Martinot, Mélissa +1 more
1. IntroductionOne of the Moon"s most surprising characteristics is its crustal asymmetry; the farside hemisphere, dominated by ancient highlands and covered with a few mare deposits, has a different volcanic history than the (sampled) nearside [1]. Surface dating of the lunar mare basalts revealed that the volcanism on the Moon lasted between ~3.…
Narrow-Line SY1 NGC 4748 in X-Rays: Detailed Case-Study
Vasylenko, A.; Fedorova, E.; Del Popolo, A.
We analyze all the available X-ray data in order to monitor the narrow-line Seyfert 1 galaxy NGC 4748, namely XMM-Newton (EPIC and OM), INTEGRAL (ISGRI and JEM-X), and SWIFT (BAT and XRT) data to study both the wide-band 0.5-195 keV spectrum and light curves in details. To this aim, we use the autocorrelation analysis of the light curves, modeling…