July 2026 - vsnet-alert - ooruri.kusastro.kyoto-u.ac.jp

[vsnet-alert 28196] TCP J02191736+2857158: growing superhump
by Hiromasa Hoke 25 Jul '26

25 Jul '26

TCP J02191736+2857158: growing superhump Moriyama-san, Stephen, Funada-san, Peter Starr and Itoh-san reported the observation. According to the data from the last three days, the object has a superhump period of ~0.048(1)d. Further observations during this phase are very important. The current magnitude is ~14mag. best regard, Kyoto University master's grade 2 Hiromasa Hoke

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[vsnet-alert 28195] TCP J02191736+2857158: possible growing superhump
by Keisuke Isogai 24 Jul '26

24 Jul '26

TCP J02191736+2857158: possible growing superhump Stephen M. Brincat and Itoh-san reported the observations. The object is now showing a possible growing superhump. The period is 0.0585 d, but it may be an alias. Further observations during this phase are very important. The current brightness is ~14 mag.

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[vsnet-alert 28193] TCP J20354364+6131329: early superhump
by Keisuke Isogai 22 Jul '26

22 Jul '26

TCP J20354364+6131329: early superhump Sahil Purabiya, Raul Michel Murillo, and Itoh-san reported the observations. The object is showing clear double-peaked early superhumps with a period of 0.0579(3) d and an amplitude of 0.03 mag. Thus, this object is undoubtedly a WZ Sge-type object. Judging from the light curve profile, this object would be discovered around the peak of the superoutburst. Continuous observations are encouraged.

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[vsnet-alert 28192] TCP J20354364+6131329: WZ Sge-type DN candidate
by Keisuke Isogai 20 Jul '26

20 Jul '26

TCP J20354364+6131329: WZ Sge-type DN candidate We posted the optical and spectroscopic observations of TCP J20354364+6131329 to ATel: https://www.astronomerstelegram.org/?read=17912 The large outburst amplitude of ~8 mag and the spectral features suggest that this object is a good candidate for a WZ Sge-type dwarf nova. This object is ~14.0 mag now. Follow-up observations are encouraged.

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[vsnet-alert 28167] TCPJ15030519+2202041: early superhump and rapid decay
by Hiromasa Hoke 18 Jul '26

18 Jul '26

TCPJ15030519+2202041: shows early superhump and rapid decay now Itoh-san, Moriyama-san, Hiraga-san, Funada-san, Magnus Larsson, and Josch Hambsch have newly reported their observations. According to the data, this object showed an early superhump with an amplitude of 0.03. Furthermore, this object has a superhump period of 0.03041(1). Now, this object shows rapid fading since May 15. AM CVn-type dwarf novae show the second outburst after an interval of several to more than ten days. This is a perfect opportunity to observe the growing superhump, so it is very important to observe this object even if it gets faint. best regard, Hiromasa Hoke

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[vsnet-alert 28190] AT2026ryu: new SU UMa-type dwarf nova, likely WZ Sge-type
by Yusuke Tampo 15 Jul '26

15 Jul '26

AT2026ryu: new SU UMa-type dwarf nova, likely WZ Sge-type Rui Min et al discovered AT2026ryu at 14.98 mag on 2026-07-06 15:01:24 UTC. The outburst amplitude is ~8 mag. ZTF also discovered this object as ZTF26abeziup. https://www.wis-tns.org/object/2026ryu https://vsx.aavso.org/index.php?view=detail.top&oid=10875920 Lesedi telescope at SAAO and Itoh-san have reported the time-resolved observations of AT2026ryu. The most recent observations on 14 July with Lesedi show ordinary superhumps with a period of ~0.0571 d. No clear modulations are present in the data on 6 and 7 July. Thus AT 2026ryu is a new SU UMa-type dwarf nova. Given its large outburst amplitude and long waiting time before the emergence of ordinary superhumps, AT 2026ryu is likely a WZ Sge-type dwarf nova. Time-resolved observations are encouraged to improve the period determination. 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 28189] ASASSN-26ea: new SU UMa-type dwarf nova, likely WZ Sge-type
by Yusuke Tampo 15 Jul '26

15 Jul '26

ASASSN-26ea: new SU UMa-type dwarf nova ASASSN-26ea was discovered by ASASSN on 2026-07-5.07 at 16.67 mag. The time-resolved observations by Sjoerd Dufoer show ordinary superhumps with a period of ~0.058 d (other aliases possible). Thus ASASSN-26ea is a new SU UMa-type dwarf nova. Considering its large outburst amplitude (~8 mag according to the VSX) and short superhump period, ASASSN-26ea can be a WZ Sge-type dwarf nova. https://vsx.aavso.org/index.php?view=detail.top&oid=10875918 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 28188] ASASSN-26dv: new SU UMa-type dwarf nova and a candidate period bouncer
by Yusuke Tampo 15 Jul '26

15 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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