Evan R. Figg

AC Piscium, A Short-Period Cool Dwarf Algol Binary

AC Piscium was found to be a near-contact, cool dwarf (K7-M4 type), short-period (P = 0.335 day) binary system. The binary is in a semidetached, Algol-type configuration. The binary could also be classified as a precontact W UMa binary. This system bears future study to further determine its absolute configuration and orbital evolution.

PHOTOMETRIC STUDY OF THE NEAR CRITICAL CONTACT SYSTEM, GSC 3355 0394

GSC 3355 0394 has an EB-type light curve, which is dominated by hot and cool spot activities. It displays night-to-night variations in light-curve shapes. The period study yields six new times of minimum light and the first precision ephemeris, HJD T{sub min}I = 2, 454, 408.9547 {+-} 0.0017 + 0.4621603 {+-} 0.0000008d*E. VR{sub c}I{sub c} standard magnitudes are presented. BVRI Wilson synthetic light-curve solutions are calculated for both a Mode 4 (V1010 Oph-type, semidetached, more massive component filling its Roche lobe) configuration and a Mode 3, contact configuration (fill-out 100% or critical contact). The critical contact is the lowest residual solution. Four major spot regions are needed to model this binary, at least one is evidently a stream spot.

The asymmetric light curves of the GSC 2764 1417 (And), GSC 3355 0394 (Per) and GSC 2537 0520 (Psc)

Solar-type variability is enhanced in short period close binaries with increased dynamo driven activity. This activity is studied in our analysis of recent light curves taken of the newly discovered eclipsing binaries GSC 2764 1417 (And), GSC 3355 0394 (Per) and GSC 2537 0775 (CVn).