... The most precisely determined characteristic for accreting neutron stars (NS's) is their period. ... Period changes show fluctuations. ... Some applications of stochastic processes in astrophysics especially in accreting systems were discussed in Lipunov (1987),Hoshino Takeshima (1993) and Lipunov (1992).In Hoshino Takeshima (1993) the authors, using simple models of MHD turbulence, try to explain aperiodic changes in X-ray luminosity of X-ray pulsars. ... Here, -constant angular momentum. ...

Russian SHAREABLE DATA CENTER Institute of Solar-Terrestial Physics SB RAS . ... Although their determination is based on the scattering process model, independent check-ups by rocket experiments have shown their correctness in experimental applications. ... Ionospheric data analysis, especially during strong disturbances, cannot be without some other kinds of diagnostic tools. ... The lack of data has always been a challange in this case. ...

... My research focusses on spectral line and dust continuum observations of star formation in the Galaxy, particularly using the JCMT. My PhD thesis involved using HARP (the Heterodyne Array Receiver Project, see also my technical pages ), an array spectrograph built in the Cavendish Astrophysics Group for the James Clerk Maxwell Telescope ( JCMT ) for a wide-field survey of star formation. ... For an overview of the survey see Curtis, Richer Buckle (2010) . ... 2010) . ... 2010 Emily Curtis | ...

Databases (NSDC) of the Natural Planetary Satellites. ... NSDC: Database of astrometric observations of Natural Planetary Satellites . ... They are thoroughly looking for observations in different sources, creating their owndatabases which are then mostly inaccessible to other researchers. ... In the file "content" with explications, the reference is given to the data source as well as the bibliographic reference. ... Data sources. ... Why a specific bibliographic database for Natural satellites? ...

... Protoplanetary Disks and the Hunt for the Youngest Exoplanets . ... Thursday, Apr 14, 2011 at 8:00 PM . ... But associating the current exoplanet properties with their formation epoch can be problematic, since the formation process is intimately associated with the physical conditions associated with their birthplaces: the disks of gas and dust that orbit young stars. ... Apr . ... Copyright (c) Amateur Telescope Makers of Boston, Inc. ...

... Ionization Properties of the Dusty Mesosphere . Boris A. Klumov, Sergey I.Popel Institute for Dynamics of Geopsheres, Russia . ... The problem of influence of the dynamics and charging of dust particles on the ionization properties of the polar summer mesosphere is considered. ... We introduce the notion "dusty mesosphere" for the layer of the mesosphere at the altitudes of approximately 80-90 km, where the conditions for the nucleation and formation of macro (dust) particles are fulfilled. ...

Authors: Yu.G. Shevelev , V.A. Marsakov , . ... We have constructed and investigated properties of metallicity function of disk stars with different ages, proceeding from the statistically restored real altitude distributions of stars at the solar galactocentric distance. It is shown that the metallicity distribution of stars in each age range is not of Gaussian form, but it may be considered as a superposition of two normal distributions centered at -0.2 and 0.0 dex. ...

... The Science Operation Department is composed of Astronomers, Telescope Instruments Operators(TIOs) and Data Handling Administrators(DHAs). ... Astronomers have proposed several methods to quantitatively measure the amount of turbulence above the telescope, which the most common ones is Differential Image Motion Monitor (DIMM). In optical testing, the Hartmann test is the common method to test the quality of optical components. ... Hartmann mask consists of 48 lenses. ...

... Spectra obtained with the 6-m telescope of SAO RAS are used along with archival data from Spitzer and several ground-based telescopes to infer a strength of PAH emission, age, properties of the UV radiation field, and metallicity of studied HII complexes. Physical properties (age, radiation field parameters, metallicity) are related to the F 8 /F 24 ratio used as a proxy for the PAH abundance in order to reveal factors that may influence the PAH evolution in HII complexes. ... Projects | ...

... These objects are predefined JavaScript objects that you access through the mimeTypes array of the navigator or Plugin object: navigator.mimeTypes[ index ] where index is either an integer representing a MIME type supported by the client or a string containing the type of a MimeType object (from the MimeType.type property). ... Property . ... The Plugin object for the plug-in that is configured for the specified MIME type If the MIME type does not have a plug-in configured, enabledPlugin is null. ...

... Solar structures oscillate · · many different oscillation periods have been identified - lots of frequency space to examine. concentrate on 3 and 5 minute wavebands. ... Identification of oscillating individual pixels, then segmentation into significant groups Data · · · · Use SPoCA active region detections. ... Analysis · · Oscillation model in each pixel dj = A cos( tj )+ B sin( tj ) Calculate (Bayesian) probability p() that the timeseries dj observed at times tj= j.t (1jN) supports a frequency . ...

... Kopylov, A.I., Kopylova, F.G. "Structure of galaxy groups and clusters and measurement of their masses", . ... Kopylova, F.G., Kopylov, A.I. "Peculiar motions of galaxy clusters and groups in the Hercules and Leo supercluster regions", . ... Kopylova, F.G., Kopylov, A.I. "Analysis of the properties of clusters of galaxies in the region of the Leo supercluster", . ... Kopylova, F.G., Kopylov, A.I. "Analysis of the properties of clusters of galaxies in the region of the Ursa Major supercluster", . ...

Physical Properties and Internal Structure of Near-Earth Objects . ... The review contains the most recent data on near-Earth objects such as their sizes and densities, rotation and shapes, taxonomy and mineralogy, optical properties and structure of their surfaces, binary systems among the NEOs and internal structure of asteroids and comets constituted the NEO population. ... The European space mission ISHTAR, NEO 4660 Nereus, NEO 5797 Bivoj. ...

... Next: Unsupervised Catalog Classification Up: Object Detection and Previous: Classification of Objects . ... Multi-resolution allows for image analysis in terms of different scales. ... This approach is used for the detection (and subsequent analysis) of globular cluster systems around elliptical galaxies, and for image characterization and object trawling in large image databases. ... The applicability of this approach to object detection in large image collections has been investigated. ...

... Astronomical Definition: self-replicating information . ... Climate Changes . Milloins of years timescale . ... Mass Extinctions in Geological History: . 500 million years ago (unclear) . ... Evidence from Fossil Record: 100-150 million year extinction periodicity ?? ... Climate Cycle ? ... Since the orbital period of the Sun around the center of the Galaxy is about 250 million years then every 100-150 million years the earth is in a spiral arm which is a region of high supernova density. ...

SOLAR POLARIZATION 5 ASP Conference Series, Vol. 405, c 2009 S. V. Berdyugina, K. N. Nagendra, and R. Ramel li, eds. Fine-scale Sto chastic Structure of Solar Magnetic Fields V. Chertoprud, B. Ioshpa, and V. Obridko Pushkov Institute of Terrestrial Magnetism, Ionosphere and Radio Wave Propagation, Russian Academy of Sciences, Troitsk, Moscow Region, 142190 Russia Abstract. ... The exponent H is 0.5­0.7 for the active region magnetic fields and 0.1 for the background field. ...

... It has been largely superceded by MatWeb . Conversion Factors . Material properties . Physical constants . Astronomical constants . This table gives conversion factors to convert various units to their SI equivalents. ... The units are SI. This is a short list of physical constants in SI units. ... Boltzmann constant . ... Gas constant . ... Mass . ... Plank's . ... Radiation constant . ... This is a short list of astronomical constants in SI units. ... Sun . ...

spaceweb@oulu.fi - last update: 11 May 1998, 1830 UT (RR) . Omega bands are large scale, discrete auroral folds or wavy structures that may sometimes develop into torch-like structures extending toward the pole (Akasofu and Kimball, 1964; Akasofu, 1974). ... Opgenoorth, H., J. Oksman, K. U. Kaila, E. Nielsen, and W. Baumjohann, On the characteristics of eastward drifting omega bands in the morning sector, J. Geophys. ... 103 , 15-27, 1998. ... Space Physics Text Book of Oulu ...

Pixels , slits and facets for the NGST NIRSpec: Appendix ST-ECF Instrument Science Report NGST 2002-01a Pixels , slits and facets for a MEMS-type spectrograph for NGST Appendix : Extension to different PSF and detector properties Santiago Arribas, Peter Jakobsen, Robert Fosbury Wolfram Freudling --1-- ST-ECF Instrument Science Report NGST 2002-01a Pixels , slits , and ... This PSF meets the two requirements established by Bely et al. for the OTA optical quality. ...

... All the galaxies are divided into 4 groups depending on the environment type; every subsample contains more than 10 galaxies. ... An effect of environments is seen both for the nuclei and for the bulges: if we consider the clusters (Virgo and Ursa Ma jor) and group centers as dense environments and the field and group periphery as sparse environments, then in the dense environments the stellar populations of S0s are in average older by 4­5 Gyr than in the sparse ones. ...