[vsnet-outburst 24560] ASASSN-20ap: likely new SU UMa-type dwarf nova

Mon Jan 20 10:26:51 JST 2020

Dear colleagues,

I have collected 3 nights of unfiltered CCD observations of ASASSN-20ap (2020, Jan 17/18, 18/19, 19/20) covering 705 observations obtained over a time span of 15.6 hours. Observations were made at CBA Belgium Observatory, using a 0.40-m f/10.0 telescope and STT-3200ME CCD camera, under mostly clear skies. 

The resulting light curve shows the presence of a superhump-like signal - during each of the 3 consecutive nights - with an amplitude of 0.05 mag. A period analysis using the ANOVA, Lomb-Scargle and PDM methods (Peranso),  yields a combined superhump period of 0.0618 +/- 0.0014d. The object was at mag 15.1 (CV) on Jan 20th. 

Observations will be sent to AAVSO, CBA and VSNET for further analysis. 

Follow-up observations are highly recommended to further study the evolution of superhumps in this system.

Best regards
Tonny

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