July 2025 - vsnet-outburst - ooruri.kusastro.kyoto-u.ac.jp

[vsnet-outburst 31534] ASASSN-25dc; a new candidate of a WZ Sge-type dwarf nova with the double superoutburst
by Yusuke Tampo 24 Jul '25

24 Jul '25

ASASSN-25dc; a new candidate of a WZ Sge-type dwarf nova with the double superoutburst ASASSN-25dc was discovered by ASAS-SN on 2025-07-13.09 UTC at g=13.07. This outburst is also observed by ATLAS, o~15.2 mag on 2025-07-07.8 UTC and o~13.5 mag on 2025-07-10.9 UTC. The likely counterpart is Gaia DR3 6129070308813533568 with G~21.0 mag, hence the outburst amplitude is ~7.0 mag. This system underwent a short dip on 16-17th July, around 14.5 mag, and is now recovering from the dip. Lesedi telescope at Sutherland, Josch Hambsh, and Berto Monard have reported the time-resolved observations of ASASSN-25dc. PDM analysis using the overall data yields a single-peaked modulation with a period of 0.05991(4) d and an amplitude of 0.03 mag. Combining the 1-mag dip feature on the light curve and short superhump period, ASASSN-25dc can be a similar system to double-superoutburst WZ Sge-type dwarf novae, especially the period-bouncer candidates ASASSN-15jd and ASASSN-16hg (see Kimura et al. 2016,2018). https://arxiv.org/abs/1604.06344 https://arxiv.org/abs/1803.03179 The ongoing second outburst should show the evolution of ordinary superhumps. The hint of ordinary superhumps is seen in the observations on 17th July. Further time-resolved observations are 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-outburst 31537] TCP J19181542+3158142: likely a new WZ Sge-type dwarf nova
by Yusuke Tampo 23 Jul '25

23 Jul '25

TCP J19181542+3158142: likely a new WZ Sge-type dwarf nova TCP J19181542+3158142 was discovered by the XOSS team on 18 July at 15.22 mag. The quiescence counterpart is a Pan-STARRS1 source with r=21.35(3) mag, indicating the outburst amplitude of ~6 mag. Itoh-san reported the time-resolved observations for three nights on 19-21 July. Although the scatter is large, PDM analysis yields a period of 0.05525(7) d, with an amplitude of ~0.1 mag and a double-peaked profile, probably early superhumps. Thus, TCP J19181542+3158142 is likely a new WZ Sge-type dwarf nova. This system is a bit faint for time-resolved observations (currently ~15.8 mag), but further observations are encouraged to confirm its superhump profile and evolution. 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-outburst 31536] Outbursts 22/07/2025
by Rod Stubbings 22 Jul '25

22 Jul '25

Outbursts observed 22/07/2025 object YYMMDD(UT) mag code remarks AQRQU 250722.556 160 Stu.RASNZ outburst ARABF 250722.419 142 Stu.RASNZ outburst CAROQ 250722.374 141 Stu.RASNZ outburst CENV342 250722.371 143 Stu.RASNZ outburst CRABP 250722.380 140 Stu.RASNZ outburst CRTBF 250722.368 144 Stu.RASNZ outburst LUPBR 250722.565 145 Stu.RASNZ outburst PAVAS 250722.428 150 Stu.RASNZ outburst PAVGS 250722.385 148 Stu.RASNZ outburst SGRV730 250722.381 151 Stu.RASNZ outburst VIRTW 250722.369 131 Stu.RASNZ outburst VIRHS 250722.431 148 Stu.RASNZ outburst ASASSN-19CT 250722.367 138 Stu.RASNZ outburst -- Rod Stubbings Tetoora Road Observatory Victoria, Australia Honorary Associate member Astronomical Society of Australia Telescope: "Infinity" 22" f/3.8 stubbo(a)dcsi.net.au http://rodstubbingsobservatory.wordpress.com/

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[vsnet-outburst 31535] Recent outbursts
by Rod Stubbings 20 Jul '25

20 Jul '25

Recent outbursts observed. object YYMMDD(UT) mag code remarks AQLFO 250717.492 146 Stu.RASNZ outburst CAROQ 250717.428 142 Stu.RASNZ outburst CENV442 250717.421 120 Stu.RASNZ outburst CENV803 250717.487 143 Stu.RASNZ outburst CIRBZ 250717.576 147 Stu.RASNZ outburst DELEZ 250717.640 149 Stu.RASNZ outburst ERICK 250717.603 136 Stu.RASNZ outburst HYAV392 250717.415 148 Stu.RASNZ outburst HYIVW 250717.471 103 Stu.RASNZ outburst INDTU 250717.481 143 Stu.RASNZ outburst INDCS 250717.476 125 Stu.RASNZ outburst NORHP 250719.607 144 Stu.RASNZ outburst PEGRU 250719.697 120 Stu.RASNZ outburst PEGHX 250719.699 131 Stu.RASNZ outburst PSATY 250717.599 118 Stu.RASNZ outburst SERRY 250717.459 150 Stu.RASNZ outburst SERUZ 250719.613 136 Stu.RASNZ outburst SGRV730 250719.609 158 Stu.RASNZ outburst TRADV 250717.627 130 Stu.RASNZ outburst TUCVW 250719.602 160 Stu.RASNZ outburst ASASSN-14BP 250717.426 149 Stu.RASNZ outburst NSV 11274 250717.443 141 Stu.RASNZ outburst DDE 77 250719.715 139 Stu.RASNZ outburst -- Rod Stubbings Tetoora Road Observatory Victoria, Australia Honorary Associate member Astronomical Society of Australia Telescope: "Infinity" 22" f/3.8 stubbo(a)dcsi.net.au http://rodstubbingsobservatory.wordpress.com/

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[vsnet-outburst 31531] TCP J19335406+4220008: new SU UMa-type dwarf nova
by tonny.vanmunster＠gmail.com 16 Jul '25

16 Jul '25

Dear colleagues, I have just completed the analysis of my unfiltered CCD observations of TCP J19335406+4220008, obtained on Jun 29/30 and Jun 30/Jul 01, 2025 at CBA Extremadura Observatory (Spain). The data was collected using a 0.40-m f/5.1 telescope and Moravian G2-4000 CCD camera under clear skies. The object was discovered by XOSS (Mi Zhang, Jianlin Xu, Guoyou Sun, Jiangao Ruan, et al.) on Jun 21st. The light curve clearly reveals the presence of regular superhumps with an amplitude of 0.13 mag, establishing TCP J19335406+4220008 as a new SU UMa-type dwarf nova. A period analysis, using the ANOVA, Lomb-Scargle, Generalized-Lomb-Scargle and PDM methods (Peranso 3.1) yields a combined superhump period of 0.0615 +/- 0.0003d. The object was measured at mag CV = 14.9 on Jul 01st. Image calibration and photometry were performed using the latest release of Phoranso, allowing us to simultaneously collect observations of 4 additional interesting VSX stars in the same FOV. Further observations are encouraged to refine the superhump period. 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 PERANSO : The Light Curve and Period Analysis Software http://www.peranso.co <http://www.peranso.com/> m PHORANSO: Photometric Reduction and Analysis Software http://www.phoranso.com <http://www.phoranso.com/>

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[vsnet-outburst 31532] Recent outbursts
by Rod Stubbings 06 Jul '25

06 Jul '25

Recent outbursts observed. object YYMMDD(UT) mag code remarks AQLPQ 250704.723 153 Stu.RASNZ outburst CAPSY 250705.514 140 Stu.RASNZ outburst CAROQ 250704.786 138 Stu.RASNZ outburst CENV342 250705.481 148 Stu.RASNZ outburst CENV803 250705.527 143 Stu.RASNZ outburst INDTT 250705.486 144 Stu.RASNZ outburst INDTU 250705.491 143 Stu.RASNZ outburst NORHP 250706.084 146 Stu.RASNZ outburst OCTAO 250704.767 150 Stu.RASNZ outburst PAVGS 250705.488 149 Stu.RASNZ outburst PEGHX 250704.756 132 Stu.RASNZ outburst SGRV3774 250704.716 148 Stu.RASNZ outburst TUCVW 250704.756 158 Stu.RASNZ outburst VELV383 250705.479 144 Stu.RASNZ outburst ASASSN-17MJ 250705.498 140 Stu.RASNZ outburst -- Rod Stubbings Tetoora Road Observatory Victoria, Australia Honorary Associate member Astronomical Society of Australia Telescope: "Infinity" 22" f/3.8 stubbo(a)dcsi.net.au http://rodstubbingsobservatory.wordpress.com/

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