2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/10080The orbital period is a measure of the size of a contact binary star, and can be combined with color to predict its luminosity to a fraction of stellar magnitude. This novel application of contact binary systems currently has limitations that we describe in the text but is potentially capable of providing a reasonable means of estimating distances to stellar systems at the level comparable to that achievable for Cepheids or other pulsating stars.review presented at Binaries in Clusters meeting, Calgary, Alberta, June 19-23, 1995. uufiles compressed Post-Script text and 4 figures. Subject to final editing and referee approvalAstrophysicstext