[vsnet-alert 24319] ASASSN-20fr: new SU UMa-type dwarf nova

Tonny Vanmunster tonny.vanmunster@gmail.com via vsnet-alert vsnet-alert at ooruri.kusastro.kyoto-u.ac.jp
Wed Jun 3 06:21:41 JST 2020

Dear colleagues,

I have just finished analysing my unfiltered CCD observations of ASASSN-20fr, obtained during 5 consecutive nights between May 28 - June 02, 2020 at CBA Belgium Observatory, using a 0.40-m f/10.0 telescope and STT-3200ME CCD camera, under clear skies.

While low amplitude modulations were visible during the initial 4 nights, clearly developed superhumps started to appear on June 01/02, with an amplitude of 0.19 mag. This establishes ASASSN-20fr as a new SU UMa-type dwarf nova (without completely ruling out a WZ Sge-type classification) . A period analysis using the ANOVA, Lomb-Scargle, Generalized-Lomb-Scargle and PDM methods (Peranso 3.0, under development), yields a combined superhump period of 0.0793 +/- 0.0012d. The object was at mag 15.7 (CV) on Jun 02nd. 

I will send my observations to AAVSO, CBA and VSNET for further analysis.

Follow-up observations are highly recommended to refine the superhump period and to study its further evolution.

Best regards

Tonny Vanmunster
CBA Belgium Observatory
CBA Extremadura Observatory

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