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

[vsnet-alert 28167] TCPJ15030519+2202041: early superhump and rapid decay
by Hiromasa Hoke 09 Jun '26

09 Jun '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 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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[vsnet-alert 28173] CM Del faint state
by Pavol A. Dubovsky 26 May '26

26 May '26

UGZ/IW type variable CM Del entered the new faint state. See my recent visual records: DELCM 20260521.140 15.30 DPV DELCM 20260523.108 15.36 DPV DELCM 20260526.135 16.02 DPV Clear Skies! -- Pavol A. Dubovsky Variable Star Section, Slovak Astronomical Society and Slovak Union of Astronomers var.kozmos.sk www.bombol.space

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[vsnet-alert 28171] Outbursts 21/05/2026
by Rod Stubbings 23 May '26

23 May '26

Outbursts and selected activity. object YYMMDD(UT) mag code remarks AQLFO 260521.663 146 Stu.RASNZ outburst AQLPQ 260521.687 153 Stu.RASNZ outburst AQLV1047 260521.687 153 Stu.RASNZ outburst AQLV1885 260521.694 150 Stu.RASNZ outburst CAROQ 260521.537 144 Stu.RASNZ active CENNN 260521.637 154 Stu.RASNZ outburst CENV803 260521.664 130 Stu.RASNZ outburst CHAST 260521.542 143 Stu.RASNZ active CRABP 260521.571 150 Stu.RASNZ active CRTBF 260521.530 147 Stu.RASNZ outburst HYAV392 260521.528 148 Stu.RASNZ outburst HYIWX 260521.729 138 Stu.RASNZ outburst HYIDR 260521.728 151 Stu.RASNZ outburst INDTT 260521.649 128 Stu.RASNZ outburst MICCM 260521.653 146 Stu.RASNZ outburst NORHP 260521.567 132 Stu.RASNZ outburst NORIK 260521.568 144 Stu.RASNZ active PAVV548 260521.647 142 Stu.RASNZ outburst PSATY 260521.704 148 Stu.RASNZ active SCOV478 260521.475 151 Stu.RASNZ active SERUZ 260521.573 132 Stu.RASNZ active SGRV2276 260521.651 153 Stu.RASNZ outburst NSV 11274 260521.558 140 Stu.RASNZ active LMC V3434 260521.499 144 Stu.RASNZ outburst MASTER OT J142023.47-485540.0 260521.713 128 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-alert 28169] AT 2026nhs = TCP J17521907+5001155 in superoutburst
by Marc Deldem 22 May '26

22 May '26

TNS AT 2026nhs (https://www.wis-tns.org/object/2026nhs) is TCP J17521907+5001155 (https://vsx.aavso.org/index.php?view=detail.top&oid=285776) UGSU Type Observations (available on AAVSO database) last night 2026-05-21 to 2026-05-22 show a superoutburst. Marc Deldem

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[vsnet-alert 28166] 2026 outburst of TCP J05454551+5954307 = ASASSN-22dq (UGWZ)
by Kirill Sokolovsky 13 May '26

13 May '26

TCP J05454551+5954307 = ASASSN-22dq (UGWZ) was found in outburst on 2026-05-13.1420 UTC at unfiltered magnitude CV=14.65 in images obtained with the NMW-TexasTech survey (135mm telephoto lens + QHY600M CMOS camera). The images are available at http://tau.kirx.net/img/TCPJ05454551+5954307/ Nothing brighter than CV~15.4 is visible at this location in images obtained the previous night on 2026-05-12.1429 with the same camera. The previous outburst of TCP J05454551+5954307 (14.7mag) was discovered on 2022-03-19.46139 by Hideo Nishimura, Kakegawa, Shizuoka, Japan. Original TOCP page: http://www.cbat.eps.harvard.edu/unconf/followups/J05454551+5954307.html VSX record: https://vsx.aavso.org/index.php?view=detail.top&oid=2227062 ZTF lightcurve: https://ztf.snad.space/dr23/view/1816212100005173 ASAS-SN lightcurve: https://asas-sn.osu.edu/sky-patrol/coordinate/077b9ec9-61b5-4dba-9a47-fc49f… Best wishes, Kirill On Tue, 29 Mar 2022, Taichi Kato wrote: > TCP J05454551+5954307: ordinary superhumps > > Observations from Crimean Astrophys. Obs. indicate > that ordinary superhump evolved on Mar. 27. >

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[vsnet-alert 28165] TCP J07151825+4753167 and TCP J15030519+2202041: new hydrogen-rich and helium-rich WZ Sge-type dwarf novae
by Hiromasa Hoke 11 May '26

11 May '26

Dear all, We posted the photometric follow-up results by Itoh-san and Moriyama-san for TCP J15030519+2202041 and our spectroscopic follow-up results for TCP J15030519+2202041 and TCP J07151825+4753167 to ATel. https://www.astronomerstelegram.org/?read=17791 We concluded that J0715+4753 is a new WZ Sge-type dwarf nova because Hα has a narrow emission core and its spectrum shows a blue continuum with the Balmer and HeI absorption lines. J1503+2202 is a new AM CVn-type dwarf nova because this object has HeI absorption lines, a temperature of ~25,000K and possible early superhump period of 0.0303(1) d. Follow-up observations are important. Especially, TCPJ1503+2202 is a long-period AM CVn star, and the opportunity to observe such an event is rare. Continuous time-series observations are strongly encouraged. best regard, Hiromasa Hoke

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[vsnet-alert 28164] Quasar S5 1803+78, optical bright state
by Stefan Karge 04 May '26

04 May '26

Quasar S5 1803+78, optical bright state Object date, UTC mag comment ------------------------------------------------------------ QSO S5 1803+78 2026-04-15,070 14.36CV active, Tns.Obs., 90mm QSO S5 1803+78 2026-04-28,083 14.53V active, BGO, 60cm QSO S5 1803+78 2026-05-01,969 14.39V active, Tns.Obs., 31.5cm CDK ------------------------------------------------------------ Taunus Observatory, MPC B01, 31.5cm CDK (Tns.Obs) Taunus Observatory, MPC B01, 90mm Apo (Tns.Obs) Burke-Gaffney Observatory, 60cm CGT (BGO) Observer: Stefan Karge (SKA) http://quasar.square7.ch/fqm/1803+784.html End

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