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Descubrimiento, Estudio, Clasificación y Modelado de Estrellas Variables Department of High and Applied Mathematics, Odessa National Maritime University, Ukraine, virnina@gmail.com
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I. Descubrimiento de Estrellas Variables
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5 steps Choosing of the field and observations Searching for new variable stars Selection of comparison stars, photometry Photometric data analysis Publishing of the results
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Determination of variability type Classical classification is available on the web-page http://sai.msu.su/groups/cluster/gcvs/gcvs/iii/vartype.txt intense variable X-ray sources Groups of types of variability: eruptive variable stars pulsating variable stars rotating variable stars cataclysmic (explosive and nova-like) variables eclipsing binary systems
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Determination of variability type The most frequent types EclipsingPulsating
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II. Modeling
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Modeling using the Wilson-Devinney (W-D) code, Monte Carlo searching algorithm
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How does the W-D code with the Monte Carlo searching algorithm work?
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First (initial) iteration
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Convergence of the iterations
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BM UMa (V-band) P=0.27123d
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Input parameters Main parameters of the system: i[80 °.. 90 ° ]– inclination T 1 4700 K (fixed)– temperature of the primary component T 2 [4100 K.. 5500 K] – temperature of the secondary component q[1.5.. 3.0]– mass ratio Ω 1 [3.95.. 6.61]– potential of the primary component Ω 2 [3.95.. 6.61] – potential of the secondary component g 1 0.32 ( fixed )– gravity brightening of the primary component A 1 0.5 ( fixed ) – reflection effect for the primary component g 2 0.32 ( fixed ) – gravity brightening of the secondary component A 2 0.5 ( fixed ) – reflection effect for the primary component e0 ( fixed ) – eccentricity p 90 ( fixed ) – periastron [-0.02.. 0.02] – phase shift
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Results of modeling parameters: Inclination 86.815 ± 0.005 T 2 4510 ± 10 mass ratio1.858 ± 0.001 Ω 1 4.986 ± 0.001 Ω 2 4.986 ± 0.001 fill-out factor10.7% 0.0017 r 1 pole 0.31 r 1 side 0.32 r 1 back 0.36 r 2 pole 0.41 r 2 side 0.44 r 2 back 0.47
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WZ Crv – a binary system with asymmetric phase curves
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Temperatures and relative radiuses
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+ Spot
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Super-WASP observations M wasp =0.3528R+0.6472V-0.1213 M wasp =580nm
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Fitting Parameters ParametersWASP-2006WASP-2007WASP-2008Our observ. Inclination, °81.2381.4381.1583.84 T 1, K12500150001480012830 T 2, K 5650565056505650 1 5.8236.3496.1855.851 2 3.4113.7313.5853.464 Mass ratio0.7960.9580.8980.807 Third light, %7.411.68.72.9 (V-band) Spot parameters Co-latitude696230160 Longitude151171160212 Radius48304356 Temp. factor0.890.530.610.73
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Spot Changes on the Primary Component ParametersWASP-2006WASP-2007WASP-2008 Co-latitude, °75 ± 251 ± 141.5 ± 0.5 Longitude, ° 155 ± 1167 ± 3154 ± 1 Radius, ° 45 ± 228 ± 157 ± 1 Temp. factor0.874 ± 0.0060.595 ± 0.0020.853 ± 0.001
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Fitting of WASP Data 200620072008
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Conclusions Advantages and Disadvantages of W-D code with MC searching algorithm + – The searching runs automatically; Only the borders of parameters are required; From the statistical point of view, the algorithm founds the best solution. Some parameters (mass ratio, inclination etc.) are too unsure; Sometimes statistically best solution is rather far from the real parameters.
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