OPTICAL AND INFRARED OBSERVATIONS OF CIRCINUS X-1

I present optical VRI and infrared JHK images of the X-ray source Circinus X-1. A superposition of the best optical and infrared images clearly shows that Cir X-1 should be identified with the southernmost of a group of three stars located within a 1".5 diameter region. Photometry is obtained from both the visible and the infrared images and is used to study the variability of the source. Cir X-1 appears as a very red point source having V - I almost-equal-to 2.9 mag and V - K almost-equal-to 10 mag during its quiescent phase.