810 research outputs found

    Determination of characteristics of newly discovered eclipsing binary 2MASS J18024395 +4003309 = VSX J180243.9+400331

    Get PDF
    During processing the observations of the intermediate polar 1RXS J180340.0+401214, obtained 26.05.2012 at the 60-cm telescope of the Mt. Suhora observatory (Krakow, Poland), variability of 2MASS J18024395+4003309 was discovered. As this object was not listed in the "General Catalogue of Variable Stars" or "Variable Stars Index", we registered it as VSX J180243.9+400331. Additionally we used 189 separate observations from the Catalina Sky Survey spread over 7 years. The periodogram analysis yields the period of 0d.3348837{\pm}0d.0000002.The object was classified as the Algol-type eclipsing binary with a strong effect of ellipticity. The depths of the primary and secondary minima are nearly identical, which corresponds to a brightness (and maybe) mass ratio close to 1. The statistically optimal degree of the trigonometric polynomial n=4. The most recent minimum occurred at HJD 2456074.4904. The brightness range from our data is 16.56-17.52 (V), 16.18-17.08 (R). The NAV ("New Algol Variable") algorithm was applied for statistically optimal phenomenological modeling and determination of corresponding parameters

    Hyperbolic Chaos of Turing Patterns

    Full text link
    We consider time evolution of Turing patterns in an extended system governed by an equation of the Swift-Hohenberg type, where due to an external periodic parameter modulation long-wave and short-wave patterns with length scales related as 1:3 emerge in succession. We show theoretically and demonstrate numerically that the spatial phases of the patterns, being observed stroboscopically, are governed by an expanding circle map, so that the corresponding chaos of Turing patterns is hyperbolic, associated with a strange attractor of the Smale-Williams solenoid type. This chaos is shown to be robust with respect to variations of parameters and boundary conditions.Comment: 4 pages, 4 figure

    Program WWZ: Wavelet Analysis of Astronomical Signals With Irregularly Spaced Arguments

    Full text link
    A program WWZ is introduced, which realizes the wavelet analysis using an improved modification of the algorithm of the Morlet wavelet for a general case of irregularly spaced data, which is typical for the databases available in virtual observatories. Contrary to the well-known analogs, working with regularly spaced (equidistant in time) arguments, we have implemented an improved algorithm presented by Andronov, (1998KFNT...14..490A, 1999sss..conf...57A), which significantly increases the signal-to-noise ratio. The program has been used to study semi-regular pulsating variable stars (U Del et al.), but can be used for the analysis of signals of any nature.Comment: 5 pages, 2 figures, "Odessa Astronomical Publications", v. 26, No.1 (in press

    Orbital stability of solutions to the problem on capillary-gravity waves in two-fluid layer

    Get PDF
    Going back to N. E. Kochin [1] problem about capillary-gravity waves on interface of two-fluid flow is considered as bifurcation problem with spectral parameters
    corecore