In responce to Victor Ruiz's request for info on period determination methods for variable stars, I compiled my 2 cents worth...

An old but nice introduction and review to the four or five most popular period finding methods can be found in [1] by Fullerton. This includes the various "string-length" methods made popular by Lafler and Kinman [2]. This method has been expanded upon by Stellingwerf [3] with the PDM method which is now a part of IRAF. Most of the people I am associated with use FFT methods as prescibed by Horne and Baliunas [4] and can now be found in the Numerical Recipes [5] book. There is also a DFT method [6] which I am not too familiar with.

I am also interested in anyone else's methods and ideas...
References:

1. The Study of Variable Stars Using Small Telescopes, Fullerton, A.W. 1986, ed. J.R. Percy, Cambridge University Press, p 201-218.
2. An RR Lyrae Survey With The Lick 20-inch Astrograph II. The Calculation of RR Lyrae Periods By Electronic Computer, Lafler, J. and Kinman, T.D. ApJS 11, p 216-222.
3. Period Determination Using Phase Dispersion Minimization (PDM), Stellingwerf, R.F. 1978, ApJ 224, 953-960.
4. A Prescription for Period Analysis of Unevenly Sampled Time Series, Horne, J. and Baliunas, S. 1986, ApJ 302, 757-763.
5. Search Algorithm For Weak Periodic Signals In Unevenly Spaced Time-Series, Press, W.H. and Teukolsky, S.A., Numerical Recipes, Cambridge Univ. Press.
6. Roberts, 1987, AJ 93, 968
   Grindlay, 1988, ApJ, 334, L25

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Jeff W. Robertson Improvise, Adapt, Overcome...Iterate. Indiana University Astronomy bigjay@astro.indiana.edu http://www.astro.indiana.edu/~bigjay

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