AX J2315-59.2

a.k.a. CP Tuc, Tuc 1

This polar CV (highly magnetic WD primary, with WD rotation period and the orbital period identical), was observed at Woomera from November 1995 to September 1998.

This source swaps between a bright active state, and a fainter (by about 3 magnitudes) inactive state. Its active light-curve appears somewhat as a skewed sinusoid; in the faint state, the Woomera data suggest that ellipsoidal modulation of the secondary may be visible, but the data are too noisy to say for certain.

The Woomera photometry yields an orbital period of 5342.31+-0.02s. A phase zero of HJD 2450033.6495, based on spectroscopy, was taken from the literature. Apart from the state-swapping, and some changes in brightness on a months-scale which may be associated with state-changing, variations in maximum brightness may be seen from cycle-to-cycle when this CV is in its high state.


Diff. mag. vs. HJD : a high-low transition is obvious, with a slight drop in maximum brightness preceeding this.


Diff. mag. vs. orbital phase : all Woomera high-state data.


Diff. mag. vs. phase : Woomera low-state data. Small dots show individual measurements; large dots with error bars show these binned with phase width 0.1. Vertical error bars show scatter within the phase bin; horizontal, show the width of the phase bin. Ellipsoidal modulation of the secondary may be visible here, although this is by no means definite.