Superhumps and grazing eclipses in the dwarf nova BG Arietis

TL;DR

This study presents photometric observations of the dwarf nova BG Arietis, revealing superhumps, grazing eclipses, and detailed outburst behavior characteristic of SU UMa type dwarf novae.

Contribution

First detailed photometric analysis of BG Arietis showing superhumps, grazing eclipses, and outburst characteristics, confirming its classification as an SU UMa type dwarf nova.

Findings

Superhump period during plateau: ~0.0850 days

Grazing eclipses with 0.06-0.13 mag depth

Outburst duration of at least 20 days

Abstract

We report unfiltered photometry of BG Arietis (= SDSS J015151.87+140047.2) in 2009 and 2010 which shows the presence of superhumps with peak-to-peak amplitude of up to 0.36 magnitudes showing this to be an SU UMa type dwarf nova. The outburst amplitude was 5.1 magnitudes above a mean quiescence magnitude of 19.9. The 2010 event lasted at least 20 days during which we observed a precursor outburst which was immediately followed by a superoutburst. Modulations were observed during the rise to superoutburst with a period approximately half Porb. The mean superhump period during the plateau phase was Psh = 0.0849(6) d, representing a superhump period excess epsilon = 0.030(7). We also observed small eclipses of depth 0.06 to 0.13 magnitude and FWHM duration of ~12 mins ({\Delta}{\Phi}1/2 = 0.10), which we interpret as grazing eclipses of the accretion disc. The 2009 superoutburst was less well observed, especially in the early stages, so we cannot tell whether there was a precursor outburst. The mean superhump period during the plateau was Psh = 0.0851(4) d, but towards the end of the plateau it suddenly decreased to Psh = 0.0845(11) d. Small eclipses were also observed.