A photoelectric study of the eclipsing binary EG Serpentis

Abstract

ABSTRACT A ubvy photoelectric study of the early A-type, detached eclipsing binary EG Serpentis (EG Ser) has been undertaken at Mount Laguna Observatory. Simultaneous observation on two telescopes has been employed for the first time at the observatory. Approximately 2000 standardized differential magnitudes are presented along with standardized colours and V magnitudes of the EG Ser field. A new ephemeris is determined that indicates a small positive displacement of secondary eclipse. The photometric elements are solved for using the NDE model, and the presence of a small, but non-zero, orbital eccentricity is confirmed. The photometry is combined with published spectroscopy to obtain absolute parameters for the system. The colour excess of and distance to the binary are determined. An approximate age is estimated. The results are compared with the only other published solution (of about the same vintage) and recent light-curve solutions by the author of this study.