RX Cassiopeiae / RX Cas
Light curves and phase diagrams of the EB type eclipsing binary RX Cassiopeiae / RX Cas.
The following light curve and phase diagram were constructed from photometry of 65 images taken with the Bradford Robotic Telescope Cluster Camera (BRT) between 2012 September 23 and 2016 October 1, and 169 images taken with the Open University COAST telescope between 2017 July 10 and 2020 April 19. The BRT data is in black, the COAST data is in red. The COAST observations were made with a Johnson V filter, but the BRT observations were made variously with no filter (CV) and a tri-colour green filter. By surreptitious choice of comparison stars with the BRT observations, the two sets of data were made 'consistent' with each other. Not rigorous science, perhaps, but the results look reasonable at this stage.
A monochrome version of the light curve and phase diagram are given below.
The above phase diagrams were plotted with a period of 32.3393 days, which was the best fit period for these particular observations as determined by Peranso. The catalogued period for this star is 32.32789d (GCVS), 32.3257d (AAVSO VSX) and 32.338d (Kreiner). There is significant o-c activity with this star (Kreiner). [Accessed 2020 April 27.]
Although the final phase diagram appears to show a lot of scatter, at least some of this appears to be due to changes in the light curve itself over different cycles. This is a complex system, and these may be due, at least in part, to the presence of an accretion disc and mass transfer between the components, as in W Ser type eclipsing binaries, see Anderson et al (1988) and Pustylnic et al (2007). Also, see AAVSO VSX page for this star.
[This page updated 2020 April 27]