[vsnet-outburst 27340] MASTER OT J210622.20+252120.4: new SU UMa-type dwarf nova

Thu Jun 10 06:28:07 JST 2021

Dear colleagues,

I have just finished analysing my unfiltered CMOS observations of MASTER OT J210622.20+252120.4, obtained on 2021, June 08/09 at CBA Belgium Observatory, using a 0.40-m f/10.0 telescope and QHY-268M CMOS camera under clear skies. 

Regular superhumps with an amplitude of 0.36 mag are clearly visible in the resulting light curve, establishing MASTER OT J210622.20+252120.4 as a new SU UMa-type dwarf nova. Note that so far this object was categorized as a possible SU UMa-type (UGSU:) in the AAVSO VSX catalogue. As noted by Taichi Kato in vsnet-outburst 24929, MASTER OT J210622.20+252120.4 showed very clear supercycles in ZTF data, but with no confirmed superhumps yet. 

A period analysis using the ANOVA, Lomb-Scargle, Generalized-Lomb-Scargle and PDM methods (Peranso 3.0), yields a combined superhump period of 0.0779 +/- 0.0009d. The object was at mag CV = 14.9 on June 08th.

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

Best regards
Tonny

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Tonny Vanmunster
CBA Belgium Observatory
CBA Extremadura Observatory
http://www.cbabelgium.com

PERANSO : The Light Curve and Period Analysis Software http://www.peranso.com