- vsnet-alert - ooruri.kusastro.kyoto-u.ac.jp

[vsnet-alert 28188] ASASSN-26dv: new SU UMa-type dwarf nova and a candidate period bouncer
by Yusuke Tampo 14 Jul '26

14 Jul '26

ASASSN-26dv: new SU UMa-type dwarf nova and a candidate period bouncer ASASSN-26dv was discovered by ASASSN on 2026-06-23.03 UT at 14.62 mag. After the initial decline, ATLAS and ASASSN light curves showed a short dip around 2026-07-05 UT. https://vsx.aavso.org/index.php?view=detail.top&oid=10875895 The time-resolved observations after this dip by Berto Monard show likely positive superhumps, with a period of ~0.055 d. Thus, ASASSN-26dv is a new SU UMa-type dwarf nova with a possible dip in the outburst plateau, which is often seen in outbursts in period bouncers. Further time-resolved observations are encouraged to establish its superhump period. 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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[vsnet-alert 28184] GK Per: outburst
by Keisuke Isogai 14 Jul '26

14 Jul '26

> Date: Sat, 11 Jul 2026 10:49:32 +0100 > From: "Bob Dryden via groups.io" <bobdryden=ntlworld.com(a)groups.io> > To: baavss-alert(a)groups.io > Subject: Re: [baavss-alert] GK Per > > Can any one confirm GK Per is slightly brighter than usual? > I had it at 12.6 this morning (11th July) > > Bob Dryden We observed GK Per about one hour earlier. The brightness was g~12.05. The object will be undergoing an outburst. I do not have posting privileges for baavss-alert, so I am posting here instead. I apologize for the inconvenience.

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[vsnet-alert 28186] TCP J02191736+2857158: a WZ Sge-type dwarf nova
by Keisuke Isogai 12 Jul '26

12 Jul '26

TCP J02191736+2857158: a WZ Sge-type dwarf nova I posted the ATel: https://www.astronomerstelegram.org/?read=17887 The spectral features and the large amplitude of ~8.5 mag suggest that this object is a new WZ Sge-type object.

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[vsnet-alert 28182] AT 2026rdg - 11.8mag nova candidate in Aquila
by Kirill Sokolovsky 02 Jul '26

02 Jul '26

DCAP238 = ZTF26abemjfk = AT 2026rdg Discovered on 2026-07-01.3049 UT at g=14.45 r=12.53. https://www.wis-tns.org/object/2026rdg Also detected with the NMW camera on 2026-07-01.8360 at CV=11.77. May be a highly reddened classical nova or a YSO activity (FUOR?). Best wishes, Kirill

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[vsnet-alert 28181] WX Cet: 2026 outburst, possible superoutburst
by Kojiguchi 23 Jun '26

23 Jun '26

WX Cet: 2026 outburst, possible superoutburst Gavin Ramsay reported that GOTO detected WX Cet in outburst on 2026 June 22. Reported magnitude: L = 11.9 (~400–700 nm). Additionally, ATLAS Forced Photometry data reveals that the outburst had already started on 2026 June 19, reaching 11.79 mag. This is its first detected outburst since 2022, and it is a possible superoutburst.

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[vsnet-alert 28180] 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-alert 28179] DO Dra entered a low state
by Pavol A. Dubovsky 14 Jun '26

14 Jun '26

The following are the CMOS observations I made once the object was out of visual reach. DRADO 20260612.8983 16.79V 0.03 DPV DRADO 20260612.8998 16.82V 0.03 DPV DRADO 20260612.9014 16.79V 0.03 DPV DRADO 20260612.9029 16.79V 0.03 DPV DRADO 20260612.9045 16.78V 0.02 DPV DRADO 20260613.8816 16.51V 0.02 DPV DRADO 20260613.8831 16.45V 0.02 DPV DRADO 20260613.8847 16.44V 0.02 DPV DRADO 20260613.8862 16.41V 0.02 DPV DRADO 20260613.8877 16.42V 0.02 DPV -- Pavol A. Dubovsky Variable Star Section, Slovak Astronomical Society and Slovak Union of Astronomers Asociación Astronómica de Piconcillo var.kozmos.sk www.bombol.space -- Observatory: Piconcillo, Andalucia, Spain Telescopes: "KK30" Newton 300/1200 mm with MII C3-16000 camera

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[vsnet-alert 28176] 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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[vsnet-alert 28175] TCPJ15030519+2202041: the 2nd superoutburst
by Keisuke Isogai 28 May '26

28 May '26

TCPJ15030519+2202041: the 2nd superoutburst Itoh-san reported that this object was brightening last night. The current brightness should be from 16 to 15 mag. Now is a good opportunity to detect the growing superhump and estimate the binary parameters. Further observations are strongly encouraged.

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[vsnet-alert 28174] TCPJ15030519+2202041: growing superhumps appeared, and will undergo the next superoutburst soon
by Keisuke Isogai 28 May '26

28 May '26

TCPJ15030519+2202041: growing superhumps will drive the next superoutburst soon Josch Hambsch, Itoh-san, Moriyama-san, and we have observed this object. The object is at about 18.8 mag now, slightly brighter than it was several days ago. Also, we detected a clear superhump tonight. This must be the growing (stage A) superhump. In this situation, this object will undergo the next superoutburst with ordinary superhumps soon. The continuous time-resolved observations are strongly encouraged. Although the current brightness of 18.8 mag is very faint for many observers, this object will brighten to about 15 mag within a few days.

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