The Accuracy of Visually Determined Times of Primary Minima of beta Lyrae-Type and W Ursae Majoris-Type Variables

Volume 3 number 2 (1974)

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Anthony D. Mallama

Ritter Astrophysical

Abstract

This paper is the sequel to the author's paper (Mallama 1974), hereafter referred to as Paper I, which evaluated the accuracy of visually timed minima of Algol-type variables. The present paper considers Beta Lyrae-type and W Ursae Majoris-type variables together because the shapes of their light curves in primary eclipse are similiar, both being quasi-sinusoidal, and therefore it is permissable to use parameters defined in the smae way when considering the accuracy of their visually timed minima. The purpose of this study is twofold: to aid the observer in selecting variables having light curves which lend themselves to accurate determination of times of minima, and to enable the person investigating period changes to estimate the standard deviation of the available visual times of minima.