MBCAA Observatory

RX J1039.7-0507

Observed: 1 Feb, 29 March, 3 Apr 2006

Michel Bonnardeau
2 Feb 2006
Updated 30 March, 4 Apr 2006

Abstract

Observations of this faint, large amplitude cataclysmic star with a small telescope are presented.

Introduction

RX J1039 is a catasclysmic variable, that is a binary star with an accreting white dwarf. This is a ROSAT X-ray source. According to Woudt & Warner (2003), the orbital period is 1.574h and the white dwarf is magnetic with a spin period of 24.07mn (an intermediate polar).

It is also a CBA target for Jan-Apr 2006.

Observations

The observations were carried out with a 203mm f/6.3 SC telescope, a Clear filter and a SBIG ST7E camera (KAF401E CCD).

Session Number of measurements

1 Feb 2006 53

29 March 2006 26

3 Apr 2006 68

Each exposure is 200s (a few 60s images at the beginning of each session).

The comparison star is GSC 4919-01359 with an assumed unfiltered magnitude of 13.8. The check star is an anonymous star at RA=10h39mn47.78s DEC=-5°07'32.4" with a measured average magnitude of 17.19 and a standard deviation of 0.15.

The light curves:

Red: RXJ1039, Blue: the check star shifted by +2 mag. The error bars are +/- the 1 sigma statistical uncertainties.

Interrupted by haze and clouds.

Orbital phase plots

The observations from Session 1 Feb 2006 may be folded with the orbital ephemeris of Woudt & Warner (2003). I need an orbital period of 0.065596 day, within the uncertainties of the ephemeris, for the maximum to be around phase 0 (therefore my measurements may be used to improve the ephemeris):