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

[vsnet-alert 28205] DDE 196 (IPHAS J043920.40+500536.6): detection of early superhumps.
by Gianluca Masi 15 Aug '26

15 Aug '26

Dear Colleagues, I performed time-resolved photometry for DDE 196 = IPHAS J043920.40+500536.6, recently spotted in outburst (vsnet-alert 28201). I collected two runs, on 15 and 16 Aug. and their analysis reveals early superhumps. The target is right now at mag. 13.0 (unfiltered, R-mags for the reference stars from GAIA DR2). Data will be send to Kyoto for further analysis. Further observations are strongly encouraged. All the best Gianluca Masi

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[vsnet-alert 28203] ASASSN-26ev: new SU UMa-type dwarf nova
by Gianluca Masi 14 Aug '26

14 Aug '26

Dear colleagues, I report time-resolved photometry for the ASASSN-26ev transient, discovered in outburst by the ASAS-SN team on 2026-08-2.15. The brightest mag. of the transient from ASAS-SN data is g=13.2 on 2026-07-29.30; assuming the quiescence magnitude from PS1 (g=21.2), we get an outburst amplitude of about 8 mags. My run covered about 2.6 hours, around 14.86 Aug. 2026 UTC; the transient was found at mag. 15.2 (unfiltered, R-mags for the reference stars from GAIA DR2). Observations were remotely performed using the 14" OTA + ST-10XME unit available at the Virtual Telescope Project facility in Manciano, Italy. Data clearly show 0.12 mags full amplitude superhumps; period analysis using PDM with Peranso 3.0 yields a superhump period of 0.055 +/- 0.012 days. This reveals that ASAS-SN-26ev is a SU UMa-type dwarf nova. Further observations are encouraged. All the best Gianluca Masi

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[vsnet-alert 28202] TCP J14515140+6613240: new SU UMa-type dwarf nova
by tonny.vanmunster＠gmail.com 14 Aug '26

14 Aug '26

Dear colleagues, The outburst of TCP J14515140+6613240 was discovered by the NMW-TexasTech survey team on 2026 Jul 29.3 UT at mag g = 13.2. The quiescent counterpart is a 21.2 g mag Pan-STARRS1 star, implying an outburst amplitude of ~8 mag. I have completed the analysis of my unfiltered CCD time-series observations of TCP J14515140+6613240, obtained on 10 out of 11 nights between 2026 Aug 03/04 and 13/14 at CBA Extremadura Observatory. The data were acquired under clear skies with a 0.40-m f/5.1 telescope and a Moravian G2-4000 CCD camera. The combined light curve clearly shows regular superhump modulations with an amplitude of 0.34 mag. A period analysis using ANOVA, Lomb-Scargle, Generalized-Lomb-Scargle and PDM methods (Peranso 3.1) yields a combined superhump period of 0.0566 +/- 0.0002d. The object was measured at mag CV = 15.7 on Aug 14th. Superhumps were absent till 2026 Aug 08/09, when they first started to appear. No early superhumps were detected with sufficient evidence. 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. The detection of superhumps with a period of 0.0566 d securely establishes TCP J14515140+6613240 as an SU UMa-type dwarf nova. The large outburst amplitude (~8 mag) might be consistent with a WZ Sge-type classification, but the absence of early superhumps does not (yet) support such classification. Continued monitoring is strongly encouraged. I will submit my observations to AAVSO, CBA and VSNET for further analysis. With kind regards, Tonny --- Tonny Vanmunster CBA Belgium Observatory CBA Extremadura Observatory http://www.cbabelgium.co <http://www.cbabelgium.com/> m

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[vsnet-alert 28199] ASASSN-26eq: new SU UMa-type dwarf nova; WZ Sge-type classification not excluded
by tonny.vanmunster＠gmail.com 09 Aug '26

09 Aug '26

Dear colleagues, The outburst of ASASSN-26eq was discovered by the ASAS-SN team on 2026 Jul 21.4 UT at mag g = 15.3. The quiescent counterpart is a 22.8 g mag Pan-STARRS1 star, implying an outburst amplitude of ~8 mag. I have completed the analysis of my unfiltered CCD time-series observations of ASASSN-26eq, obtained on 4 nights between 2026 Aug 04/05 and 08/09 at CBA Extremadura Observatory. The data were acquired under clear skies with a 0.40-m f/5.1 telescope and a Moravian G2-4000 CCD camera. The combined light curve clearly shows regular superhump modulations with an amplitude of 0.14 mag. A period analysis using ANOVA, Lomb-Scargle, Generalized-Lomb-Scargle and PDM methods (Peranso 3.1) yields a combined superhump period of 0.0622 +/- 0.0020d. The object was measured at mag CV = 16.6 on Aug 09th. 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. The detection of superhumps with a period of 0.0622 d securely establishes ASASSN-26eq as an SU UMa-type dwarf nova. The large outburst amplitude (~8 mag) is consistent with the WZ Sge subclass of dwarf novae. As our coverage began 14 days after the discovery, the presence of early superhumps prior to Aug 04/05 could not be assessed from our data, so a WZ Sge-type classification cannot be excluded. Continued monitoring for possible post-outburst rebrightenings would help to further support a WZ Sge-type classification, should one occur. I will submit my observations to AAVSO, CBA and VSNET for further analysis. With kind regards, Tonny --- Tonny Vanmunster CBA Belgium Observatory CBA Extremadura Observatory http://www.cbabelgium.co <http://www.cbabelgium.com/> m

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[vsnet-alert 28195] TCP J02191736+2857158: possible growing superhump
by Keisuke Isogai 23 Jul '26

23 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 14 Jul '26

14 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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