[vsnet-alert 22845] ASASSN-18abn: new SU UMa type dwarf nova

Sat Dec 15 10:15:15 JST 2018

Dear colleagues,

I have just concluded the analysis of my 2018, Dec 14/15 unfiltered CCD photometry session of ASASSN-18abn. Observations were made at CBA Extremadura Observatory (Spain),  using a 0.40-m f/5.1 telescope and SX-46 CCD camera, under a very clear sky. Note that the telescope had a downtime of >3 weeks due to a hardware issue with the focuser.

The resulting light curve clearly shows the presence of superhumps with an amplitude of 0.40 mag, hence classifying this object as a new SU UMa type dwarf nova. A period analysis using the ANOVA, Lomb-Scargle and PDM methods (Peranso), yields a combined superhump period of 0.0603 +/- 0.0008d. The object was at mag 15.0 (CV) on Dec 14th. 

The rising trend of the superhump profile shows additional low-amplitude, periodic ‘humps’. I leave it up to professional astronomers to comment on possible interpretations of these low-amplitude humps.

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

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