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N. Jevtic (Richard Stockton College), J.S. Schweitzer (University of Connecticut)
The light curve of DB white dwarf PG 1351+489 has a broadband power spectrum. Nonlinear time series analysis using time-delay phase space reconstruction is one way to deal with such nonlinear signals. However, the utility of this method is greatly diminished by noise. For PG 1351+489 or any variable whose trajectory in phase space lies on an identifiable manifold, noise that takes the phase space point off the trajectory can greatly be reduced using local nonlinear projective noise reduction. The novel tool of three-dimensional Poincare section return time (and hence, frequency) amplitude spectra is proposed for the identification of such noise resetting. In the case of PG 1351+489, the result is a white noise tail that is lower by about 50 times. For the first time, with this access to a wider range of frequencies, the question of the relative amplitudes between different lines in this power spectrum can be addressed satisfactorily. It is found that the amplitudes of the strong lines in the power spectrum of PG 1351+489 vary logarithmically with frequency.
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Bulletin of the American Astronomical Society, 36 5
© 2004. The American Astronomical Society.