Leonardo da Vinci’s ceativity and attention deficit hyperactivity disorder

The article discusses a correlation between the character and life of Leonardo da Vinci and possible manifestations of his attention deficit disorder

Analysis of the Social Significance of Obtaining the Profession of a Specialist in the Field of Physical Culture and Sports

В статье рассматривается социальная значимость получения профессии специалиста в области физической культуры и спорта на современном этапе. Анализируются особенности сферы физической культуры и спорта, а также проблемы трудоустройства выпускников.The article considers the social significance of obtaining a profession of a specialist in the field of physical culture and sports at the present stage. The features of the sphere of physical culture and sports, as well as the problems of employment of graduates are analyzed

Kinematic Control of the Inertiality of the System of Tycho-2 and UCAC2 Stellar Proper Motions

Based on the Ogorodnikov-Milne model, we analyze the proper motions of Tycho-2 and UCAC2 stars. We have established that the model component that describes the rotation of all stars under consideration around the Galactic y axis differs significantly from zero at various magnitudes. We interpret this rotation found using the most distant stars as a residual rotation of the ICRS/Tycho-2 system relative to the inertial reference frame. For the most distant ($d\approx900$ pc) Tycho-2 and UCAC2 stars, the mean rotation around the Galactic y axis has been found to be $M_{13}=-0.37\pm0.04$ mas yr$^{-1}$. The proper motions of UCAC2 stars with magnitudes in the range $12-15^m$ are shown to be distorted appreciably by the magnitude equation in $\mu_\alpha\cos\delta$, which has the strongest effect for northern-sky stars with a coefficient of $-0.60\pm0.05$ mas yr$^{-1}$ mag$^{-1}$. We have detected no significant effect of the magnitude equation in the proper motions of UCAC2 stars brighter than $\approx11^m$.Comment: 15 pages, 6 figure

Galactic Rotation Parameters from Data on Open Star Clusters

Currently available data on the field of velocities Vr, Vl, Vb for open star clusters are used to perform a kinematic analysis of various samples that differ by heliocentric distance, age, and membership in individual structures (the Orion, Carina--Sagittarius, and Perseus arms). Based on 375 clusters located within 5 kpc of the Sun with ages up to 1 Gyr, we have determined the Galactic rotation parameters Wo =-26.0+-0.3 km/s/kpc, W'o = 4.18+-0.17 km/s/kpc^2, W''o=-0.45+-0.06 km/s/kpc^3, the system contraction parameter K = -2.4+-0.1 km/s/kpc, and the parameters of the kinematic center Ro =7.4+-0.3 kpc and lo = 0+-1 degrees. The Galactocentric distance Ro in the model used has been found to depend significantly on the sample age. Thus, for example, it is 9.5+-0.7 kpc and 5.6+-0.3 kpc for the samples of young (50 Myr) clusters, respectively. Our study of the kinematics of young open star clusters in various spiral arms has shown that the kinematic parameters are similar to the parameters obtained from the entire sample for the Carina-Sagittarius and Perseus arms and differ significantly from them for the Orion arm. The contraction effect is shown to be typical of star clusters with various ages. It is most pronounced for clusters with a mean age of 100 Myr, with the contraction velocity being Kr = -4.3+-1.0 km/s.Comment: 14 pages, 4 figures, 2 table

The relevance of existential experience of time

The article is devoted to the philosophy of man and his relation to time within the framework of existentialism. The topic of time in existentialism is very relevant today. What is still important for a modern person: the past, the future or the present?Статья посвящена философии человека и его отношению к времени в рамках экзистенциализма. Тема экзистенциального переживания времени очень востребована в наши дни. Тем самым, возникает вопрос, что же всё-таки важно для современного человека: прошлое, будущее или настоящее

Photometric study of open clusters Berkeley 96, Berkeley 97, King 12, NGC 7261, NGC 7296, and NGC 7788

The BVRcIc CCD photometry in the fields of six open clusters toward the Perseus spiral arm is presented. These data along with JHKs magnitudes taken from 2MASS catalog, have been used to determine cluster's ages, distances and color excesses. In addition, the gaps in mass function of Be 97, King 12 and NGC 7788 clusters have been revealed in mass intervals of 1.3-1.5, 1.4-1.6 and 1.5-1.7 solar masses, respectively.Comment: 11 pages, 12 figure

Analysis of Peculiarities of the Stellar Velocity Field in the Solar Neighborhood

Based on a new version of the Hipparcos catalogue and an updated Geneva-Copenhagen survey of F and G dwarfs, we analyze the space velocity field of about 17000 single stars in the solar neighborhood. The main known clumps, streams, and branches (Pleiades, Hyades, Sirius, Coma Berenices, Hercules, Wolf 630-alpha Ceti, and Arcturus) have been identified using various approaches. The evolution of the space velocity field for F and G dwarfs has been traced as a function of the stellar age. We have managed to confirm the existence of the recently discovered KFR08 stream. We have found 19 Hipparcos stars, candidates for membership in the KFR08 stream, and obtained an isochrone age estimate for the stream, 13 Gyr. The mean stellar ages of the Wolf 630-alpha Ceti and Hercules streams are shown to be comparable, 4--6 Gyr. No significant differences in the metallicities of stars belonging to these streams have been found. This is an argument for the hypothesis that these streams owe their origin to a common mechanism.Comment: 23 pages, 9 figure

The OSACA Database and a Kinematic Analysis of Stars in the Solar Neighborhood

We transformed radial velocities compiled from more than 1400 published sources, including the Geneva--Copenhagen survey of the solar neighborhood (CORAVEL-CfA), into a uniform system based on the radial velocities of 854 standard stars in our list. This enabled us to calculate the average weighted radial velocities for more than 25~000 HIPPARCOS stars located in the local Galactic spiral arm (Orion arm) with a median error of +-1 km/s. We use these radial velocities together with the stars' coordinates, parallaxes, and proper motions to determine their Galactic coordinates and space velocities. These quantities, along with other parameters of the stars, are available from the continuously updated Orion Spiral Arm CAtalogue (OSACA) and the associated database. We perform a kinematic analysis of the stars by applying an Ogorodnikov-Milne model to the OSACA data. The kinematics of the nearest single and multiple main-sequence stars differ substantially. We used distant (r\approx 0.2 kpc) stars of mixed spectral composition to estimate the angular velocity of the Galactic rotation -25.7+-1.2 km/s/kpc, and the vertex deviation,l=13+-2 degrees, and detect a negative K effect. This negative K effect is most conspicuous in the motion of A0-A5 giants, and is equal to K=-13.1+-2.0 km/s/kpc.Comment: 16 pages, 8 figure

Peculiar Features of the Velocity Field of OB Associations and the Spiral Structure of the Galaxy

Some of the peculiar features of the periodic velocity-field structure for OB associations can be explained by using the model of Roberts and Hausman (1984), in which the behavior of a system of dense clouds is considered in a perturbed potential. The absence of statistically significant variations in the azimuthal velocity across the Carina arm, probably, results from its sharp increase behind the shock front, which is easily blurred by distance errors. The existence of a shock wave in the spiral arms and, at the same time, the virtually free motion of OB associations in epicycles can be reconciled in the model of particle clouds with a mean free path of 0.2-2 kpc. The velocity field of OB associations exhibits two appreciable nonrandom deviations from an ideal spiral pattern: a 0.5-kpc displacement of the Cygnus- and Carina-arm fragments from one another and a weakening of the Perseus arm in quadrant III. However, the identified fragments of the Carina, Cygnus, and Perseus arms do not belong to any of the known types of spurs.Comment: 14 pages, 3 postscript figures, to be published in Astronomy Letter

Изменчивость морского льда в Арктике по данным Арктического портала

The Arctic Portal of the Laboratory of Satellite Oceanography of the Russian State Hydrometeorological University is an open geo-informational system designed for operational monitoring of the sea ice–ocean–atmosphere system in the Arctic. Possibilities to use the Arctic Portal for the Arctic sea ice monitoring on the basis of satellite data, as well as the types of satellite measurements suitable for studying the properties of sea ice: active and passive microwave data; data of spectral radiometers in the infrared  (IR) and visible ranges are considered. Every type of satellite data has certain limitations. For the study of sea ice the most suitable are the all-season remote sensing data  – measurements of microwave instruments, independent of clouds and time of a day. Existing in the world resources of the sea ice maps and satellite data on sea ice are either closed for users or limited in their informational content. Several types of satellite data are currently available on the Arctic portal: Sentinel-1 synthetic aperture radar (SAR) images, 8-day averaged MODIS reflectivity data, optical and IR MODIS data of original time and spatial resolution, Norwegian Meteorological University sea ice maps, and data on consolidation of sea ice, based on passive microwave radiometer measurements. Some data is additionally available in the test mode. The effectiveness of combined use of various satellite data on the sea ice is proved by the examples of sea ice analyses.Представлены возможности Арктического портала (геоинформационного сервиса) для мониторинга ледяного покрова Арктики на основе спутниковых данных. Дан обзор основных типов спутниковых инструментов, позволяющих изучать морской лёд. Обоснована эффективность совместного применения результатов обработки разных спутниковых данных, имеющихся в среде геосервиса