Dear colleagues,
TCP J20143906+0352503 was discovered by XOSS (Xingming Observatory Sky Survey) on 2025 Sep 16.7 at mag 15.72C. The quiescent counterpart is possibly a 21.1 V mag star 2" to the W, implying an outburst amplitude of ~5 mag.
I have just completed the analysis of my unfiltered CCD observations of TCP J20143906+0352503, obtained on 2025 Sep 22/23 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 clearly exhibits superhump modulations with an amplitude of 0.25 mag. Period analysis with ANOVA, Lomb-Scargle, Generalized-Lomb-Scargle and PDM methods (Peranso 3.1) yields a combined superhump period of 0.0641 +/- 0.0006d. The object was measured at mag CV = 16.4 on Sep 23rd.
Additional observations obtained on earlier nights (e.g. Sep 21/22) also showed superhump activity; however, the data sets were too short due to clouds to permit a reliable period determination.
Image calibration and photometry were performed with the latest release of Phoranso, which enabled simultaneous photometry of several additional variable stars within the same frames.
These results establish TCP J20143906+0352503 as a new SU UMa-type dwarf nova. Follow-up observations are encouraged.
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.co http://www.cbabelgium.com/ m
PERANSO : The Light Curve and Period Analysis Software
http://www.peranso.co http://www.peranso.com/ m
PHORANSO: Photometric Reduction and Analysis Software