August 2026 - 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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