[vsnet-alert 22496] ASASSN-18rg: new very short period SU UMa type dwarf nova

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

Dear colleagues,

I have just concluded the analysis of my 2018, Sep 06/07 unfiltered CCD photometry session of ASASSN-18rg. Observations were made at CBA Extremadura Observatory (Spain),  using a 0.40-m f/5.1 telescope and SX-46 CCD camera, under very clear skies. 

 

The resulting light curve clearly reveals the presence of “superhumps” with an amplitude of 0.10 mag, hence classifying this object as a new SU UMa type dwarf nova. A preliminary period analysis using the ANOVA, Lomb-Scargle and PDM methods (Peranso), yields a combined superhump period of 0.0340 +/- 0.0008d.  This is a very short period system, so I leave it up to the professional astronomers to comment on possible different interpretations of this periodic signal. E.g., this might be growing ‘stage A superhumps’, as commented by Kojiguchi Naoto (VSNET Kyoto Univ team) in vsnet-outburst 22607. The object was at mag 13.9 (CV) on Sep 07th.  I will publish above lightcurve on the “Cataclysmic Variables” Facebook page.

 

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

 

Follow-up observations are highly recommended to further refine the superhump period. 

 

Best regards
Tonny


 

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

 <http://www.peranso.com> www.peranso.com