[vsnet-alert 23665] Is ASASSN-19zy a new SU UMa-type dwarf nova?

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

Dear colleagues,

I have just concluded the analysis of my 2019, Oct 27/28 unfiltered CCD photometry session of ASASSN-19zy. Observations were made at CBA Belgium Observatory, using a 0.40-m f/10.0 telescope and STT-3200ME CCD camera, under clear skies. 

 

The resulting light curve shows complex modulations with 0.10 mag amplitude, possibly resembling superhumps, in which case this object would qualify as a new SU UMa-type dwarf nova. A period analysis using the ANOVA, Lomb-Scargle and PDM methods (Peranso),  yields a possible periodicity of 0.057 +/- 0.002d. The object was at mag 15.75 (CV) on Oct 18th. Note that the object has been spectroscopically confirmed to be a dwarf nova in outburst [ATEL #13232,  <mailto:lina.tomasella at inaf.it> L. Tomasella et al]

 

The classification of ASASSN-19zy as a possible SU UMa-type is still uncertain and requires follow-up observations. I’m currently clouded out at both my CBA Belgium and CBA Extremadura Observatories, maybe even for a few nights. I would appreciate the help of other amateurs to continue monitoring this target, in order to determine its exact nature.

Observations will be sent 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 <http://www.cbabelgium.com> 
www.peranso.com <http://www.peranso.com>