Dear colleagues,

TCP J22135399+3015357 was discovered by the NMW survey at the Astroverty astrofarm in Russia on 2025 Aug 19.8 at mag 13.6 CR. Archival images show that the object was already in outburst one day earlier. The quiescent counterpart is listed at 22.8 r mag, implying an outburst amplitude of ~9 mag.

I have just completed the analysis of my unfiltered CCD observations of TCP J22135399+3015357, obtained on 2025 Aug 20/21 at CBA Extremadura Observatory. The data were acquired under clear skies with a 0.40-m f/5.1 telescope and a Moravian G2-4000 CCD.

The light curve reveals clear double-peaked modulations consistent with early superhumps, with an amplitude of 0.11 mag. A period analysis, using ANOVA, Lomb-Scargle, Generalized-Lomb-Scargle and PDM methods (Peranso 3.1) yields a combined superhump period of 0.0612 +/- 0.0012d. The object was measured at mag CV = 14.2 on Aug 20th.

Image calibration and photometry were performed with the latest release of Phoranso.

These findings strongly suggest that TCP J22135399+3015357 is a new WZ Sge-type dwarf nova. Continued monitoring is strongly encouraged to study the superhump profile and evolution.

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

With kind 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

PHORANSO: Photometric Reduction and Analysis Software

http://www.phoranso.com