The Nature of the Variable Star GSC 3206.00873

Emily Fryer

Advisor: Dr. Thomas Balonek

Star GSC 3206.00873 is a comparatively bright star (R ≈ 12.6 mag.) in the vicinity of the quasar BL Lacertae.  Once considered a candidate as a comparison star for the quasar, it was found to be a periodic variable by Caler (2000).  This study is a continuation of that preliminary study.  The goal is to use the available optical data to determine the nature of GSC 3206.00873.  It has an amplitude of about 0.1 magnitudes.  An analysis of color-color diagrams indicated that the spectral classification the star is early F to late G Period analysis has shown a primary period of about 2.79 days and a possible secondary period of about 10.86 years.  There are also indications that the 2.79 day period is changing over time.  Given these characteristics, GSC 3206.00873  appears to be a short period, low amplitude δCepheid, a subclass that is sometimes referred to as s- or sine-Cepheids.