AAVSO: American Association of Variable Star Observers

Methods for O-C (Observed Minus Computed) Diagrams and for the Determination of Light Elements of Variable Stars with Linear and Second Order Polynomial Ephemerides

Volume 42 number 2 (2014)

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Roy Andrew Axelsen
P. O. Box 706, Kenmore, Queensland 4069, Australia; reaxelsen@gmail.com

Abstract

Methods are described for the construction and analysis of O–C (observed minus computed) diagrams and for the determination of light elements (ephemerides) of variable stars and the standard errors of the elements. The methods described are those that apply: (1) when the period of the star is constant, and (2) when the period of the star is changing continuously, and the light elements can be represented by a second order polynomial function.