Gaia24amv: SU UMa-type dwarf nova near the period gap

ATel #17906; D. Yu. Rusanova (ASPD TShNU of Kyiv), A. O. Simon (ASPD TShNU of Kyiv), W. Ogloza (UKEN, Cracow; Silesian Planetarium Chorzow), N. Karaman (Adiyaman Univ.), A. Yu. Korosko (ASPD TShNU of Kyiv), P. J. Mikolajczyk (U. Wroclaw/NCBJ, PL), L. Wyrzykowski (U. Warsaw/NCBJ, PL/EASST. eu), K. Kotysz (U. Wroclaw/U. Warsaw, PL)
on 19 Jul 2026; 12:15 UT
Credential Certification: Andrew Simon (skazhenijandrew@gmail.com)

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We report the results of photometric observations of the cataclysmic variable Gaia24amv/ZTF18ablqsov/AT2019dkz obtained during its 2026 June-July superoutburst.

On 2026 June 25, photometric observations carried out at the Observational Station Lisnyky of Taras Shevchenko National University of Kyiv, Ukraine, showed that the object had brightened to a magnitude of 16.48 mag, indicating the onset of an outburst. Extended time-series photometric observations were therefore performed on the following night (26/27 June 2026). The observations covered the interval MJD 61217.88515-61218.00942, corresponding to approximately 3 hours. The light curve (Fig. 1) clearly reveals superhumps with a preliminary period of 0.09 d and a peak-to-peak amplitude of approximately 0.3 mag. The presence of superhumps confirms that the object is an SU UMa-type dwarf nova.

To refine the period, observations were carried out during the following nights. The observational campaign covered 2026 June 26-July 4 using the 0.7-m f/4 AZT-8 telescope at the Observational Station Lisnyky of Taras Shevchenko National University of Kyiv, the 0.6-m f/6.5 ADYU60 reflector at the Observatory of Adiyaman University and 0.7-m f/6.5 PlaneWave CDK-700 telescope at Planetarium Slaskie in Chorzow. Detailed light curves are available on the object's BHTOM page. Using the combined photometric data, the superhump period was estimated with the Lomb-Scargle periodogram implemented in SciPy (scipy.signal.lombscargle), yielding a superhump period of P_sh = 0.091(3) d (Fig. 2). This superhump period suggests that the orbital period is likely close to the period gap. All the materials can be found on A.O. Simon's personal website.

Further observations are strongly encouraged. Observers are invited to upload their photometric observations to the object's BHTOM page, where all submitted data are automatically processed: https://bhtom.space/public/targets/Gaia24amv.

BHTOM is based on the open-source TOM Toolkit by LCO and has been developed with funding from the OPTICON-RadioNet Pilot (ORP) of the European Union's Horizon 2020 research and innovation programme under grant agreement No 101004719 (2021-2025). This project has received funding from the European Union's Horizon Europe Research and Innovation programme ACME under grant agreement No 101131928 (2024-2028).