The orbital and superhump periods of the SU UMa-type dwarf nova V1212 Tauri

Abstract

We report CCD photometry of the superoutburst of the dwarf nova V1212 Tau obtained during 2011 January and February. The outburst amplitude was at least 6 magnitudes and it lasted at least 12 days. Three distinct superhump regimes were observed. Initially low amplitude superhumps (0.03 to 0.05 magnitude peak-to-peak) with Psh = 0.0782(52) d were present. The superhumps reached a maximum amplitude of 0.31 magnitudes at the beginning of the plateau phase, with Psh = 0.07031(96) d. Subsequently the star began to fade slowly. During the first part of the decline, the period increased with dPsh/dt = +1.62(9) x 10-3 and the amplitude of the superhumps also declined. Mid way through the slow decline, the superhumps partially regrew and this point coincided with a change to a new superhump regime during which the period decreased with dPsh/dt = -1.50(39) x 10-3. We determined the orbital period as Porb = 0.06818(64) d and the superhump period excess as epsilon = 0.034(15)

Accepted for publication in the Journal of the British Astronomical Association. 15 pages, 4 figures