[vsnet-alert 26021] TCP J17532723+0054257: new WZ Sge-type dwarf nova

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

Dear colleagues,

I have collected unfiltered CCD observations of TCP J17532723+0054257 during
10 successive nights between 2021, Jun 22 and Jul 01. All observations were
made at CBA Extremadura Observatory, using a 0.40-m f/5.1 telescope and
SX-46 CCD camera, under clear skies. 

The object faded from mag 15.0 (CV) on Jun 22 to mag 15.8 (CV) on Jul 01, so
at a rate of 0.09 mag/d, without a clear sign of (early or regular)
superhumps in the light curve, except for the 2 last nights (Jun 29/30 and
Jun 30/Jul 01). Those 2 sessions clearly show the presence of superhumps
with an amplitude of 0.17 mag. A period analysis using the ANOVA,
Lomb-Scargle, Generalized-Lomb-Scargle and PDM methods (Peranso 3.0), yields
a combined superhump period of 0.0623 +/- 0.0003d. 

The superhump profile shows no signs of a double-waved pattern, and I could
not detect early superhumps in my data. Yet, the large outburst amplitude of
~8 mag, and the long time for superhumps to develop (approx. 9 days) make
this a very likely WZ Sge-type dwarf nova. Follow-up observations are
recommended to further track the evolution of the superhumps.

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

Best regards
Tonny

--
Tonny Vanmunster
CBA Belgium Observatory
CBA Extremadura Observatory
www.cbabelgium.com
www.peranso.com