The analysis of indexed astronomical time series – X. Significance testing of O−C data |
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| Authors: | Chris Koen |
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| Institution: | Department of Statistics, University of the Western Cape, Private Bag X17, Bellville, 7535 Cape, South Africa |
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| Abstract: | It is assumed that O ? C ('observed minus calculated') values of periodic variable stars are determined by three processes, namely measurement errors, random cycle-to-cycle jitter in the period, and possibly long-term changes in the mean period. By modelling the latter as a random walk, the covariances of all O ? C values can be calculated. The covariances can then be used to estimate unknown model parameters, and to choose between alternative models. Pseudo-residuals which could be used in model fit assessment are also defined. The theory is illustrated by four applications to spotted stars in eclipsing binaries. |
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| Keywords: | methods: data analysis methods: statistical stars: variables: other |
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