Photometry of the X-ray transient CI Cam - opportunity for CCD observers
Abstract
We present selected parts of an analysis of the photometric observations of the unique X-ray transient CI Cam (XTE J0421+560) which cover the interval after the 1998 outburst. The activity of this system continues even after this outburst, albeit with a considerably smaller amplitude. We show that, at present, the variations of brightness display the largest amplitude in the I filter (about 0.3 mag). We also show the complicated variations of the color indices and present a brief physical interpretation. We also searched for the rapid variations of brightness. The intranight variations appear to be very small, not larger than ~0.02 mag; the longt-term variations thus play the dominant role. The main purpose of this paper is to show that CCD data obtained by the instruments accessible also to the amateur observers can be very heplful in studying such an interesting, relatively bright and physically very important object, and to attract further observers.
- Publication:
-
Open European Journal on Variable Stars
- Pub Date:
- November 2007
- Bibcode:
- 2007OEJV...75...24S