Title: Hubble Space Telescope Ultraviolet Light Curves Reveal Interesting Properties of CC Sculptoris and RZ Leonis Author: Paula Szkody, Anjum S. Mukadam, Odette Toloza, Boris T. Gänsicke, Zhibin Dai, Anna F. Pala, Elizabeth O. Waagen, Patrick Godon, Edward M. Sion
Time-tag ultraviolet data obtained on the Hubble Space Telescope in 2013 reveal interesting variability related to the white dwarf spin in the two cataclysmic variables RZ Leo and CC Scl. RZ Leo shows a period at 220s and its harmonic at 110s, thus identifying it as a likely Intermediate Polar (IP). The spin signal is not visible in a short single night of ground based data in 2016, but the shorter exposures in that dataset indicate a possible partial eclipse. The much larger UV amplitude of the spin signal in the known IP CC Scl allows the spin of 389s, previously only seen at outburst, to be visible at quiescence. Spectra created from the peaks and troughs of the spin times indicate a hotter temperature of several thousand degrees during the peak phases, with multiple components contributing to the UV light.
HST/COS is scheduled to observe the eclipsing SU UMa-type dwarf nova RZ Leo:
The HST team will be making a final decision on observing RZ Leo based on the observations of April 9/10, and observations from the following night will also be essential. Close monitoring of RZ Leo through April 12 is requested to be sure it is below the threshold brightness and to have a good magnitude value for correlation with the HST observations. RZ Leo is V=18.7 at minimum and can be as bright as V=11.1 at maximum. Read more