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arXiv · 1805.09615

OAO/MITSuME Photometry of Dwarf Novae. III. CSS130418:174033+414756

Akira Imada·Keisuke Isogai·Kenshi Yanagisawa·Nobuyuki Kawai
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Abstract

We report on multicolour photometry of the short period dwarf nova CSS130418:174033+414756 during the 2013 superoutburst. The system showed an unusually short superhump period with 0.046346(67) d during stage A, which is one of the shortest periods among dwarf novae below the period minimum. We found that the bluest peaks in $g' - I_{\rm c}$ colour variations tend to coincide with the brightness minima of the superhump modulations. We also studied nightly-averaged superhump amplitudes in $g'$, $R_{\rm c}$, and $I_{\rm c}$ bands and found that they have less dependence on wavelength. These properties are likely to be in common with dwarf novae exhibiting superhumps. We successfully obtained $g' - R_{\rm c}$ and $R_{\rm c} - I_{\rm c}$ colours during the temporal dip. The colour indices were significantly bluer compared with other dips of WZ Sge-type dwarf novae. By using the period of the growing superhumps, we estimated the mass ratio to be $q$ = 0.077(5), which is much larger than the previous study.

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Akira Imada, Keisuke Isogai, Kenshi Yanagisawa, Nobuyuki Kawai. 2018-05-24. OAO/MITSuME Photometry of Dwarf Novae. III. CSS130418:174033+414756. https://doi.org/10.1093/pasj%2Fpsy074

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