UY Camelopardalis Possibly Has an Unseen Companion

Abstract

We used a 50 cm telescope plus a Princeton Instrument Vers Array 512B CCD atXinglong station of the National Astronomical Observatory of China to observe UY Cam inFebruary 2008 and totally 7 times of maximum light were obtained. We used omc01.exesoftware for (O-C) analysis and found that its pulsation period is steadily increasing with arate of about 4.8 ?? 10-9 per year. This is reasonable from the stellar evolution theory point ofview. We conclude that it has an unseen companion with an orbital period of about 49.5years. Due to few observations of this variable star, we call for more people to observe andcollect more data on this star.

Keywords: variable stars, Delta Scuti, HADS, period changes, light time effect. Stellarevolution