Dear colleagues,
I have just completed the analysis of my unfiltered CCD observations of ASASSN-25cu, obtained on Jun 27/28 and 28/29, 2025 at CBA Belgium Observatory. The data was collected using a 0.40-m f/10.0 telescope and QHY-268M CMOS camera under clear skies.
The light curve clearly reveals the presence of regular superhumps with an amplitude of 0.25 mag, establishing ASASSN-25cu as a new SU UMa-type dwarf nova. A period analysis, using the ANOVA, Lomb-Scargle, Generalized-Lomb-Scargle and PDM methods (Peranso 3.1) yields a combined superhump period of 0.0536 +/- 0.0014d. The object was measured at mag CV = 15.7 on Jun 29th.
Image calibration and photometry were performed using the latest release of Phoranso.
Further observations are encouraged to refine the superhump period.
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
PERANSO : The Light Curve and Period Analysis Software
PHORANSO: Photometric Reduction and Analysis Software