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June 2026

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[vsnet-campaign-dn 17583] ASASSN-26dq (aka Gaia DR3 375654744699712512): new SU UMa-type dwarf nova
by tonny.vanmunster＠gmail.com 19 Jun '26

19 Jun '26

Dear colleagues, ASASSN-26dq (aka Gaia DR3 375654744699712512) was found in outburst by the ASAS-SN team on 2026 Jun 07.4 at mag g = 13.6. The quiescent counterpart is a 20.4 r mag star, implying an outburst amplitude of approximately 7 magnitudes. I obtained unfiltered CCD time-series photometry of ASASSN-26dq on 2026 Jun 13/14, Jun 15/16 and Jun 18/19, at CBA Extremadura Observatory using a 0.40-m f/5.1 telescope equipped with a Moravian G2-4000 CCD camera. Modulations were already apparent in the June 13/14 light curve, but the observing run was too short for a reliable period determination. Combining the three datasets in Peranso 3.1 allowed a robust period analysis using ANOVA, Lomb-Scargle, Generalized Lomb-Scargle and PDM methods. This revealed regular superhumps with an amplitude of 0.27 mag and a superhump period of 0.0567 +/- 0.0024 d. The object faded from mag 14.5 (unfiltered) on Jun 14th to mag 15.0 (unfiltered) on Jun 19th. Image calibration and photometry were carried out using the latest release of Phoranso, which enabled simultaneous photometry of additional variable stars in the same field of view. These observations establish ASASSN-26dq as a new SU UMa-type dwarf nova. Continued time-series photometry is encouraged to refine the superhump period and monitor its evolution throughout the outburst. The observations will be submitted to AAVSO, CBA and VSNET for further analysis. With kind regards, Tonny Vanmunster CBA Belgium Observatory CBA Extremadura Observatory http://www.cbabelgium.co <http://www.cbabelgium.com/> m

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[vsnet-campaign-dn 17582] TCP J00560713+4301406: new large-amplitude outburst, likely a dwarf nova
by Yusuke Tampo 01 Jun '26

01 Jun '26

TCP J00560713+4301406: new large-amplitude outburst, likely a dwarf nova TCP J00560713+4301406 was discovered at 12.2 mag on 2026 06 01.4 UTC. http://www.cbat.eps.harvard.edu/unconf/followups/J00560713+4301406.html ATLAS also detected this outburst on 2026 05 31.6 UTC around 15.5 mag, likely on the rise. There is a possible counterpart at ~3" away; Gaia 375654744699712512 at ~20.36 mag, thus, the outburst amplitude is ~8 mag. Its blue color (BP-RP~0.34 mag) and distance 1049(-400/+1016) pc are consistent with a counterpart being a CV with a low mass-transfer rate. Although the visibility is not great, time-resolved photometry or snap spectroscopy to confirm its nature is encouraged. Best regards, Yusuke -- ---------------------------------------------- South African Astronomical Observatory, Postdoc fellow Yusuke TAMPO / 反保雄介 EMAIL: tampo(a)kusastro.kyoto-u.ac.jp ALT. EMAIL: yusuke(a)saao.ac.za ----------------------------------------------

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