Photomeric analysis of eclipsing binaries: VY UMI, RU UMI AND GSC 04364-00648

We present the photometric analysis of \textit{BVR} and \textit{TESS} light curves of three eclipsing binaries (RU~UMi and purely studied VY~UMi, GSC 04364-00648), together with their period changes considering archival data and new minima times from our and \textit{TESS} observations. For the first time we detected wave-like variations with low-amplitude in $O-C$ residua of RU UMi, which can be interpreted as a consequence of the light-time effect caused by the 3rd invisible component with period 7370 days. Period increase with rate 2.56(9)$\times10^{-7}$~d/yr$^{-1}$ detected in the VY UMi system corresponds to mass transfer from the secondary to the primary component. For GSC 04364-00648 binary system we find some quadratic changes on the $O-C$ diagram, which corresponds to a period decrease with a high rate of $-2.26(5)\times10^{-5}$~d/yr$^{-1}$. We cannot assumptions about their nature, mainly due to short time of observation and uneven coverage of $O-C$ diagram. We also determined the absolute parameter of their components using the photometric solution and \textit{GAIA} distances.Comment: accepted to REVISTA MEXICANA DE ASTRONOM\'IA Y ASTROF\'ISICA. arXiv admin note: text overlap with arXiv:2102.0983

Scaling slowly rotating asteroids with stellar occultations

Context. As evidenced by recent survey results, the majority of asteroids are slow rotators (spin periods longer than 12 h), but lack spin and shape models because of selection bias. This bias is skewing our overall understanding of the spins, shapes, and sizes of asteroids, as well as of their other properties. Also, diameter determinations for large (>60 km) and medium-sized asteroids (between 30 and 60 km) often vary by over 30% for multiple reasons. Aims. Our long-term project is focused on a few tens of slow rotators with periods of up to 60 h. We aim to obtain their full light curves and reconstruct their spins and shapes. We also precisely scale the models, typically with an accuracy of a few percent. Methods. We used wide sets of dense light curves for spin and shape reconstructions via light-curve inversion. Precisely scaling them with thermal data was not possible here because of poor infrared datasets: large bodies tend to saturate in WISE mission detectors. Therefore, we recently also launched a special campaign among stellar occultation observers, both in order to scale these models and to verify the shape solutions, often allowing us to break the mirror pole ambiguity. Results. The presented scheme resulted in shape models for 16 slow rotators, most of them for the first time. Fitting them to chords from stellar occultation timings resolved previous inconsistencies in size determinations. For around half of the targets, this fitting also allowed us to identify a clearly preferred pole solution from the pair of two mirror pole solutions, thus removing the ambiguity inherent to light-curve inversion. We also address the influence of the uncertainty of the shape models on the derived diameters. Conclusions. Overall, our project has already provided reliable models for around 50 slow rotators. Such well-determined and scaled asteroid shapes will, for example, constitute a solid basis for precise density determinations when coupled with mass information. Spin and shape models in general continue to fill the gaps caused by various biases

Relationship between hand and eye preferences

This study evaluated the relationship between hand and eye preferences in 343 men and 290 women aged between 18 and 42 years (22.11±2.07). Right-handed men preferred their right eyes, whereas left-handed men preferred their left eyes (p .05), but a significant difference was observed between left-eye preference and a preference for both eyes (p = .008). Right-handed women preferred their right eyes, whereas left-handed women preferred their left eyes (p .05). The results suggest that cultural differences among study groups and individual differences within study groups explain the inconsistencies regarding hand and eye preferences. Moreover, the findings broaden our knowledge about eye preference in relation to hand preference in a Turkish population. © Universitätsverlag Ulm GmbH 2008

REVOLTING EFFECTS IN OWN ROTATION OF HIGH-ORBITAL SATELLITES

Character of own satellites rotation is analysed, depending on the height of their flight. Results of determination of size of indignations which have influence on a rotation of the probed objects are brought. On the basis of the got results the attempt of estimation of relative change of sun permanent on solar period is done

Asteroid phase curves using sparse Gaia DR2 data and differential dense light curves

The amount of sparse asteroid photometry being gathered by both space- and ground-based surveys is growing exponentially. This large volume of data poses a computational challenge owing to both the large amount of information to be processed and the new methods needed to combine data from different sources (e.g. obtained by different techniques, in different bands, and having different random and systematic errors). The main goal of this work is to develop an algorithm capable of merging sparse and dense data sets, both relative and differential, in preparation for asteroid observations originating from, for example, Gaia, TESS, ATLAS, LSST, K2, VISTA, and many other sources. We present a novel method to obtain asteroid phase curves by combining sparse photometry and differential ground-based photometry. In the traditional approach, the latter cannot be used for phase curves. Merging those two data types allows for the extraction of phase-curve information for a growing number of objects. Our method is validated for 26 sample asteroids observed by the Gaia mission.Comment: 10 pages, 7 figures (supplementary material: 20 pages, 58 figures

A method of immediate detection of objects with a near-zero apparent motion in series of CCD-frames

The paper deals with a computational method for detection of the solar system minor bodies (SSOs), whose inter-frame shifts in series of CCD-frames during the observation are commensurate with the errors in measuring their positions. These objects have velocities of apparent motion between CCD-frames not exceeding three rms errors (3σ) of measurements of their positions. About 15% of objects have a near-zero apparent motion in CCD-frames, including the objects beyond the Jupiter’s orbit as well as the asteroids heading straight to the Earth. The proposed method for detection of the object’s near-zero apparent motion in series of CCD-frames is based on the Fisher f-criterion instead of using the traditional decision rules that are based on the maximum likelihood criterion. We analyzed the quality indicators of detection of the object’s near-zero apparent motion applying statistical and in situ modeling techniques in terms of the conditional probability of the true detection of objects with a near-zero apparent motion. The efficiency of method being implemented as a plugin for the Collection Light Technology (CoLiTec) software for automated asteroids and comets detection has been demonstrated. Among the objects discovered with this plugin, there was the sungrazing comet C/2012 S1 (ISON). Within 26 min of the observation, the comet’s image has been moved by three pixels in a series of four CCD-frames (the velocity of its apparent motion at the moment of discovery was equal to 0.8 pixels per CCD-frame; the image size on the frame was about five pixels). Next verification in observations of asteroids with a near-zero apparent motion conducted with small telescopes has confirmed an efficiency of the method even in bad conditions (strong backlight from the full Moon). So, we recommend applying the proposed method for series of observations with four or more frames