... 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. ...

... Subject and Problems of Stellar Astronomy. ... Plane of Galaxy, Methods of Its Location Determination. ... Stars Distances. ... Other Methods of Stars Distances Determination. ... Tangential Velocities, Their Determination by Self-Motions. ... Determination of Solar Apex and Spatial Velocity by Radial and Spatial Velocities of Stars. ... Features of Orientation and Parameters of Peculiar Stellar Velocities Ellipsoid. ... General and Selective Light Absorption in Galaxy. ... Darc Clouds in Galaxy. ...

For some applications you need to know how fast the model correction changes with az, za so you can estimate the error you make if you evaluate the model at a "nearby" point. ... This can be useful if you want to evaluate the model correction for the current az,za but you have the az,za position of the previous second. ... This is the maximum that the az,za can move in 1 second. 3rd: The change in the az, za errors if you move the az,za position by the model error at that position. ...

... Tonight's Sky . ... The Magazine . ... Observing . ... Magazine . ... Sky this Month . ... The double star 54 Leonis, spiral galaxy NGC 3198, and emission nebula NGC 3199 . ... Astronomy for Kids . ... Observing springtime deep-sky objects with a large telescope . ... Capturing the night's "flying flames" . ... Get instant access to subscriber content on Astronomy.com! ... Receive news, sky-event information, observing tips, and more from Astronomy's weekly email newsletter. ... Astronomy Magazine ....

... More on 51 Peg: . The discovery of a Jupiter--mass planet in orbit around the solar--type star 51Peg has been reported by Michel Mayor and Didier Queloz (Geneva Observatory) on October 6th at the 9th Cambridge workshop on "cool stars, stellar systems, and the sun" held at Florence (Italy). ... Recall that the measurements of radial velocity only yield v sin i which in turn gives us M sin i. For most values of i, sin i will be greater than 0.5 and this gives a mass estimate of 0.5 Jupiter masses. ...

... THE SIMPLEST MODEL. ... 13, Moscow 119992, Russia E-mail: san@sai.msu.ru Abstract: The analysis of the simplest model shows that an asteroid ­ rubble pile evolves, depending on the parameter V2d (where V is the average velocity of fragments and d is the average distance between fragments), either as a conglomerate of "independent mutually gravitating clusters" (when V2d < fm, where f is the gravitational constant and m is the average mass of a fragment) or as a "receding cluster" (when V2d > fm). ...

... The directives provided by mod_access are used in <Directory> , <Files> , and <Location> sections as well as .htaccess files to control access to particular parts of the server. ... The Allow and Deny directives are used to specify which clients are or are not allowed access to the server, while the Order directive sets the default access state, and configures how the Allow and Deny directives interact with each other. ... The Allow directive affects which hosts can access an area of the server. ...

. Physical Review E 55,1590-1599 (1997). Jacques Lewalle, jlewalle@syr.edu

... We present a computer program for modelling energy flux distribution and light curves of eclipsing binaries from far ultraviolet to infrared regions. The Roche model is assumed. Proximity effects of components (reflection of radiation and surface gravity darkening) are taken into account. ... Figure 1: The surface temperature distribution for Algol A-B system before (upper plot) and after (lower plot) correction for temperature due to the irradiation effect. ...

In order to measure the density of the Universe, it is necessary to sample a region that is larger than the scale on which the Universe becomes approximately homogeneous. ... When applied to clusters of galaxies we find a mass to luminosity ratio that implies a density of the Universe that is about 0.3 times the critical density. ... Thus the mass-to-muinosity ratio appears to vary with the size of the region measured, from 3 in the solar neighborhood to 30 in galaxies to 300 in clusters of galaxies. ...

... St Petersburg 23, September 2014 1 Motivation · Origin of Martian moons? ... Considered error sources: ­ Phobos a priori ephemerides; ­ Phobos a priori GM value; ­ measurements noise; ­ different strategies; · Methods: ­ real data analysis; ­ simulations. ... St Petersburg 23, September 2014 8 Simulations: sensitivity of the measurements to the a priori GM value Simulations: zero noise+ IMCCE a priori ephemerides +GMPH = 7.16 * 105 m3/sec2. ... St Petersburg 23, September 2014 14 Thank you! ...

The technical memorandum: Time and Time Interval Measurement with Application to Computer and Network Performance Evaluation (PostScript) describes a number of techniques for conducting experiments typical of computer network and transmission systems engineering. ... The usual data collected during a performance run of some experiment might include time offsets, time delays, frequency offsets and various error statistics. ...

System Throughput and SNR / Exposure Time Estimation . ... Given the SNR, Equations 6.6, 6.7, or 6.14 can be solved for the exposure time, t. Since there are time-dependent and time-independent noise sources, quadratic equations are obtained. For example, we may solve equation 6.6 for the point source exposure time: . where the term A contains the time-independent noise sources . and B contains the time-dependent noise sources . ...

... Comet Hale Bopp Over Indian Cove . ... Comet Hale-Bopp, the Great Comet of 1997, was quite a sight. In the above photograph taken on 1997 April 6, Comet Hale-Bopp was imaged from the Indian Cove Campground in the Joshua Tree National Park in California, USA. ... Still intact, on November 21 Comet ISON (C/2012 S1) swept into this animated field of view (left) from the HI-1 camera on the STEREO-A spacecraft. ... Heavy Black Hole Jets in 4U1630 47 . ... The Magnificent Tail of Comet McNaught . ...

... Thanks to special permission from Cambridge University Press, we are able to bring you the complete Numerical Recipes in Fortran 77 book On-Line! ... 1.0 Introduction 1 . ... 2.4 Tridiagonal and Band Diagonal Systems of Equations 42 . ... 3.2 Rational Function Interpolation and Extrapolation 104 . ... 7.2 Transformation Method: Exponential and Normal Deviates 277 . ... 9.6 Newton-Raphson Method for Nonlinear Systems of Equations 372 . ... 12.3 FFT of Real Functions, Sine and Cosine Transforms 504 . ...

Bizyaev D., "The Argument Against Long Extragagalactic Distance Scale", Astron. ... Soviet Astronomy) 1997. ... Zasov A., Bizyaev D., "An Estimate of the Hubble Constant using a Criterion for Gravitational Stability of Gaseous Discs", Pis'ma v Astron. ... 1996. ... D.Bizyaev, "Types of galaxies", 1996, Zvezdochet, No 11, p.22 (in Russian) . D.Bizyaev, "The Hubble Constant", 1996, Zvezdochet, No 2, p.20 (in Russian) . D.Bizyaev, "Magellanic Clouds", 1995, Zvezdochet, No 6, p.12. (in Russian) . ...

... 8, ``Celestial Mechanics'', 2002 Estimation of masses of some minor planets from observations of perturbed bodies O. M. Kochetova Institute of Applied Astronomy, St. Petersburg, Russia The most straightforward method of mass determination of minor planets is the dynamical one which uses the gravitational perturbations produced by minor planet in the motion of other bodies. ... The values of the masses of minor planets (15), (29) and (65) appear to be rather close in both papers. ...

... We study an algebraic equation P (x, y ) = 0 over a field Fp , where p is a prime. ... p We study the upper bound of the number solutions of the polynomial equation, such that x g1 G, y g2 G. The estimate #{(x, y ) | ... This estimate was obtained by a different method in the paper [1]. ... 3] (With S. Makarychev) The number of solutions of polynomial equation over the field Fp and new bounds of additive energy // Proceedings of the Conference Diferential Equations and Related Topics, 2015, p. 24-26...

... Links . ... A sell out show at the exhibit Capture the Cosmos with astronomy art by children from four schools across Cork City, Scoil na Croise Naofa, Mahon, Scoil Padre Pio, Churchfield, St. MaryтАЩs on the Hill N.S., Knocknaheeny and North Presentation ... benefited five primary schools (Olarash, Mlimani, Enguiki, Arkatan and Lashaine) from the Arusha region within the Monduli District in Tanzania , (one of the largest regions inhabited by the Maasai tribe) ...

... 2. ui , i- , : 5 ui = ( - sin cos i cosi - cos i sini T ), i (1) i ­ i- OYZ; i ­ i- OYZ, i = 225 - 90 i, i = 1,.. ... 6 max ( L1 , L2 ) nmax = min ( L1 , L2 ) ( nmax + 1) , nmax = min ( L1 , L2 ) max ( L1 , L2 ) - min ( L1 , L2 ) - . ... 3) D1min1 , D1min 2 7 mi n1min1 , n2 n1 , min 2 min 2 n1 , n2 , Dlast . ... 11) OX OXY : nxy = nijk - ( nijk , ez ) ez , (12) ex , ey , ez ­ . ... nxy , ex ) ( , ( nxy , ex ) < 0 -arccos nxy (13) OX OXZ : nxz = nijk - ( nijk , ey ) ey . ... 450 B2 (+225 ) B1 (-225 )...