The Eccentric Eclipsing Binary V889 Aquilae

Several new times of minimum light recorded with photoelectric or CCD means have been gathered for the eccentric eclipsing binary V889 Aql (P = 11.1 days, e = 0.37). Its O–C diagram is presented, and improved elements of the apsidal motion and the light-time effect (LITE) are given. We found a long apsidal motion period of about 24 400 ± 2400 years and a period of the third body of about 52 ± 2 years.     

Ccd Photometry of Neglected Eclipsing Binaries – Kz Dra, Lr Cam and Im Vul

We present ephemerides and solutions of one Algol-type (KZ Dra) and two overcontact systems (LR Cam and IM Vul) based on V(RI)_C CCD observations obtained in the project Prosper (network of amateur observers).     

Cosmology and a flat space

A theory of gravitation in a flat space is briefly described, which gives a completely new view on cosmological problems. Instead of expansion of the Universe, a contraction of bodies and clusters is obtained. This theory excludes the closed solutions as non-physical ones and gives a simple condition for the stability of gravitationally-bounded systems with respect to cosmological gravitational field.     

Analytical continuation of the gravity field for a two-dimensional body using an infinite series

Summary A procedure is derived which enables the analytical continuation of a two-dimensional gravity field to be expressed in the form of an infinite series. For this purpose, an apparatus is used which represents the two-dimensional analogy of Bicadze-type integrals.

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On Methods for the Light Curves Extrema Determination

We present two methods for the determination of moments of extrema and their errors appropriate for the analysis of light variations of variable objects. The method I is suitable for determination of times of extrema of non-periodical variables or objects, whose light curves vary. The method II is apt for O-C analyses of objects whose light curves are more or less repeating. Both methods are displayed on the analysis of BL Cam light variations and compared with the Kwee-van Woerden method.     

Computation of gravity anomalies caused by three-dimensional bodies of arbitrary shape and arbitrary varying density

Summary A numerical method is proposed which enables a direct computation of the vertical gravity anomaly due to three-dimensional bodies of arbitrary shape and with an inhomogeneous density distribution. The bodies are approximated by an assembly of appropriate curved finite elements. Gravity effects of such elements are calculated using the Gaussian quadrature formula. The integration domain is simply a cube, into which all the finite elements are transformed. The accuracy of the method is tested on a numerical example.     

Multi-Scale Gaussian Normalization for Solar Image Processing

Extreme ultra-violet images of the corona contain information over a wide range of spatial scales, and different structures such as active regions, quiet Sun, and filament channels contain information at very different brightness regimes. Processing of these images is important to reveal information, often hidden within the data, without introducing artefacts or bias. It is also important that any process be computationally efficient, particularly given the fine spatial and temporal resolution of Atmospheric Imaging Assembly on the Solar Dynamics Observatory (AIA/SDO), and consideration of future higher resolution observations. A very efficient process is described here, which is based on localised normalising of the data at many different spatial scales. The method reveals information at the finest scales whilst maintaining enough of the larger-scale information to provide context. It also intrinsically flattens noisy regions and can reveal structure in off-limb regions out to the edge of the field of view. We also applied the method successfully to a white-light coronagraph observation.     

Eclipsing Binaries with Possible Light-Time Effect

The period changes of six eclipsing binaries have been studied with focus on the light-time effect. With the least squares method we also calculated parameters of such an effect and properties of the unresolved body in these systems. With these results we discussed the probability of presence of such bodies in the systems with respect to possible confirmation by another method. In two systems we also suggested the hypothesis of fourth body or magnetic activity for explanation of the "second-order variability" after subtraction of the light-time effect of the third body.