[vsnet-alert 25139] ASASSN-20pt: new SU UMa-type dwarf nova

[Tonny Vanmunster tonny.vanmunster@gmail.com via vsnet-alert]

Dear colleagues,

I have just finished analysing my unfiltered CCD observations of ASASSN-20pt, obtained tonight (2020, Dec 17/18) at CBA Belgium Observatory, using a 0.40-m f/10.0 telescope and (partially functioning) STT-3200ME CCD camera under clear skies. 

Regular superhumps with an amplitude of 0.30 mag are clearly visible in the resulting light curve, establishing ASASSN-20pt as a new SU UMa-type dwarf nova. A period analysis using the ANOVA, Lomb-Scargle, Generalized-Lomb-Scargle and PDM methods (Peranso 3.0, release end of December), yields a combined superhump period of 0.0761 +/- 0.0027d. The object was at mag 16.7 (CV) on Dec 18th.

The superhump profile shows no signs of a double-waved pattern, making it less likely that this is a WZ Sge-type dwarf nova (despite the large outburst amplitude of ~7.5 mag). Follow-up observations are recommended to further track the evolution of the superhumps.

I will send my observations (currently large backlog) to AAVSO, CBA and VSNET for further analysis.

Best regards
Tonny

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Tonny Vanmunster
CBA Belgium Observatory
CBA Extremadura Observatory
www.cbabelgium.com
www.peranso.com