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

[vsnet-outburst 31607] Outbursts 28/12/2025
by Rod Stubbings 29 Dec '25

29 Dec '25

Outbursts and selected activity. object YYMMDD(UT) mag code remarks CENMU 251228.646 141 Stu.RASNZ outburst CENV342 251228.639 154 Stu.RASNZ outburst CENV442 251228.642 135 Stu.RASNZ active CENV485 251228.684 153 Stu.RASNZ active CHAST 251228.658 142 Stu.RASNZ active CMAWZ 251228.507 147 Stu.RASNZ active CMAHL 251228.512 120 Stu.RASNZ active CNCGZ 251228.634 130 Stu.RASNZ active CRTBF 251228.641 147 Stu.RASNZ outburst ERICK 251228.617 132 Stu.RASNZ active ERILT 251228.524 156 Stu.RASNZ active HYAV495 251228.633 145 Stu.RASNZ active MONCW 251228.533 128 Stu.RASNZ active OCTAA 251228.662 148 Stu.RASNZ outburst ORICN 251228.531 146 Stu.RASNZ active ORIV1159 251228.528 140 Stu.RASNZ outburst PAVV548 251228.489 143 Stu.RASNZ outburst PUPCL 251228.519 143 Stu.RASNZ active PUPHO 251228.523 143 Stu.RASNZ active TRADV 251228.692 134 Stu.RASNZ active TRAEK 251228.688 114 Stu.RASNZ active VELV383 251228.637 136 Stu.RASNZ active VIRTW 251228.649 129 Stu.RASNZ active ASASSN-19CT 251228.646 155 Stu.RASNZ active NSV 35 251228.663 152 Stu.RASNZ active SSS 100511:061754-362655 251228.497 154 Stu.RASNZ active -- 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 31606] Outbursts 27/12/2025
by Rod Stubbings 28 Dec '25

28 Dec '25

Outbursts and selected activity. object YYMMDD(UT) mag code remarks CENV442 251227.655 132 Stu.RASNZ active CENV485 251227.665 152 Stu.RASNZ outburst CHAST 251227.517 136 Stu.RASNZ outburst CMAWZ 251227.502 148 Stu.RASNZ active CMADM 251227.497 153 Stu.RASNZ active CMAHL 251227.496 119 Stu.RASNZ active CNCSY 251227.706 128 Stu.RASNZ active CNCGZ 251227.652 133 Stu.RASNZ active ERICK 251227.626 132 Stu.RASNZ active ERILT 251227.532 153 Stu.RASNZ active ERIPS 251227.631 127 Stu.RASNZ active HYAV495 251227.651 146 Stu.RASNZ active HYIVW 251227.671 105 Stu.RASNZ active INDTU 251227.483 143 Stu.RASNZ outburst LEOX 251227.702 148 Stu.RASNZ active MONCW 251227.544 128 Stu.RASNZ outburst ORICN 251227.539 139 Stu.RASNZ active PUPCL 251227.527 147 Stu.RASNZ outburst PUPHO 251227.531 143 Stu.RASNZ active TRADV 251227.697 132 Stu.RASNZ active TRAEK 251227.694 112 Stu.RASNZ active VELV383 251227.621 134 Stu.RASNZ active VIRTW 251227.688 132 Stu.RASNZ active ASASSN-14GR 251227.467 151 Stu.RASNZ outburst ASASSN-19CT 251227.658 154 Stu.RASNZ active NSV 35 251227.519 150 Stu.RASNZ outburst SSS 100511:061754-362655 251227.467 152 Stu.RASNZ active MASTER OT J142023.47-485540.0 251227.700 130 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 31605] TCP J16425922+2621020: a large amplitude CV candidate, likely a WZ Sge-type dwarf nova
by Yusuke Tampo 27 Dec '25

27 Dec '25

TCP J16425922+2621020: a large amplitude CV candidate, likely a WZ Sge-type dwarf nova Tadashi Kojima reported the discovery of TCP J16425922+2621020 on 2025 12 26.8538 UTC at 13.0 mag (unfiltered). http://www.cbat.eps.harvard.edu/unconf/followups/J16425922+2621020.html The likely counterpart is 3"-away Gaia DR3 1301247792154799488, G=20.044(8) mag at 674 (-144/+248) pc. Thus, the absolute magnitudes in quiescence and outburst are ~10.9(7) and ~3.9(7) mag, respectively. This is also recorded in the Gaia white dwarf candidate catalogs (e.g., Gentile et al. 2021). http://vizier.cds.unistra.fr/viz-bin/VizieR?-source=&-out.add=_r&-out.add=_… Given its large outburst amplitude of ~7 mag, no previous outbursts, and possible white dwarf-dominated spectral energy distribution in quiescence, TCP J16425922+2621020 is most likely a WZ Sge-type dwarf nova in outburst. Although time-resolved observations are almost impossible for now due to its RA=16hr, this might be a nice target for future observations. 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 31604] outbursts 26/12/2025
by Rod Stubbings 27 Dec '25

27 Dec '25

Outbursts and selected activity. object YYMMDD(UT) mag code remarks CENV442 251226.669 131 Stu.RASNZ outburst CNCGZ 251226.726 132 Stu.RASNZ outburst ERICK 251226.604 132 Stu.RASNZ outburst ERILT 251226.608 154 Stu.RASNZ outburst ERIPS 251226.657 128 Stu.RASNZ outburst HYAV495 251226.696 154 Stu.RASNZ outburst HYIWX 251226.606 140 Stu.RASNZ outburst HYIVW 251226.694 102 Stu.RASNZ outburst LEOX 251226.696 138 Stu.RASNZ active MENAD 251226.660 153 Stu.RASNZ outburst ORICN 251226.615 134 Stu.RASNZ active TRADV 251226.721 131 Stu.RASNZ outburst TRAEK 251226.715 116 Stu.RASNZ outburst VELV383 251226.632 130 Stu.RASNZ outburst VIRTW 251226.699 132 Stu.RASNZ outburst ASASSN-19CT 251226.674 142 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 31603] Outbursts 22,23/12/2025
by Rod Stubbings 24 Dec '25

24 Dec '25

Outbursts and selected activity. object YYMMDD(UT) mag code remarks ARAV793 251222.481 147 Stu.RASNZ outburst CAROQ 251222.533 148 Stu.RASNZ active CAROQ 251223.499 146 Stu.RASNZ active CMAWZ 251222.506 155 Stu.RASNZ outburst CMADM 251223.502 147 Stu.RASNZ outburst CMAHL 251223.501 119 Stu.RASNZ outburst INDTT 251222.515 154 Stu.RASNZ active PAVGS 251222.518 150 Stu.RASNZ outburst PEGHX 251222.477 131 Stu.RASNZ outburst PUPBV 251222.507 143 Stu.RASNZ active PUPBX 251222.506 155 Stu.RASNZ active PUPHO 251222.542 140 Stu.RASNZ active VOLSY 251222.532 160 Stu.RASNZ active ASASSN-14FF 251222.494 150 Stu.RASNZ active DDE 76 251222.492 156 Stu.RASNZ outburst LMC V3434 251222.527 146 Stu.RASNZ outburst SSS 100511:061754-362655 251222.483 144 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 31602] HW Boo
by Gary Poyner 23 Dec '25

23 Dec '25

The UGSU star HW Boo is in bright outburst, possibly a superoutburst, the first one since March 2024... Dec 17.447 17.678V Dec 18.540 17.500V Dec 21.535 13.911V AAVSOnet DSO-35, Fort Davis, Texas. Gary -- ------------------------------------------------------ Gary Poyner FRAS garypoyner(a)gmail.com www.variablestars.co.uk

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[vsnet-outburst 31601] ASASSN-22nd (=AT2025ahnc= ZTF25acibbkf =ASASSN-25fb); a new fast-decaying outburst
by Yusuke Tampo 19 Dec '25

19 Dec '25

ASASSN-22nd (=AT2025ahnc= ZTF25acibbkf =ASASSN-25fb); a new fast-decaying outburst GOTO, ZTF, and ASASSN have detected a new outburst from a known CV candidate ASASSN-22nd. https://vsx.aavso.org/index.php?view=detail.top&oid=2345330 https://www.wis-tns.org/object/2025ahnc https://lasair-ztf.lsst.ac.uk/objects/ZTF25acibbkf/ https://asas-sn.osu.edu/sky-patrol/coordinate/19517db9-fb36-4d9c-a94d-2ca87… This outburst shows a fast decay, approximately 1 mag/d. Considering its large amplitude(>7mag), relatively short outburst cycle (~3 years), and fast decay of the outburst, this outburst could be a precursor outburst of a dwarf nova superoutburst, or even from an AM CVn star. Although the system is currently faint (~18.5 mag in ATLAS), if the system returns to a bright state, time-resolved photometries will be 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 31600] Outbursts 16,17/12/2025
by Rod Stubbings 17 Dec '25

17 Dec '25

Outbursts and selected activity. object YYMMDD(UT) mag code remarks CENMU 251216.671 134 Stu.RASNZ active CENV342 251216.624 154 Stu.RASNZ active CENV803 251216.680 136 Stu.RASNZ active CNCSY 251216.701 113 Stu.RASNZ outburst ERIBF 251216.494 138 Stu.RASNZ active ERIBF 251217.476 139 Stu.RASNZ active GEMUV 251216.620 150 Stu.RASNZ active HYAV392 251216.662 143 Stu.RASNZ active INDTT 251216.471 131 Stu.RASNZ active INDTT 251217.462 131 Stu.RASNZ active OCTAA 251216.599 148 Stu.RASNZ outburst ORIBI 251216.500 142 Stu.RASNZ active ORIBI 251217.542 141 Stu.RASNZ active ORICN 251216.501 137 Stu.RASNZ outburst ORICN 251217.543 134 Stu.RASNZ active ORICZ 251217.549 134 Stu.RASNZ outburst PICAR 251216.487 157 Stu.RASNZ outburst PICAR 251217.489 132 Stu.RASNZ active PUPBV 251216.522 136 Stu.RASNZ outburst PUPBV 251217.535 138 Stu.RASNZ active PUPBX 251217.534 150 Stu.RASNZ outburst PUPCL 251216.524 143 Stu.RASNZ active PUPCL 251217.535 148 Stu.RASNZ active PUPHO 251216.521 139 Stu.RASNZ outburst PUPHO 251217.553 140 Stu.RASNZ active PYXVZ 251216.574 132 Stu.RASNZ outburst PYXVZ 251217.560 151 Stu.RASNZ active TUCVW 251216.596 158 Stu.RASNZ outburst ASASSN-14FF 251216.492 148 Stu.RASNZ outburst ASASSN-14FF 251217.478 151 Stu.RASNZ active -- 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 31594] ASASSN-25eq: new WZ Sge-type dwarf nova, likely a period bouncer
by Yusuke Tampo 17 Dec '25

17 Dec '25

ASASSN-25eq: new WZ Sge-type dwarf nova, likely a period bouncer ASASSN discovered ASASSN-25eq on 2025-11-13.18 UT at 15.07 mag. Then it brightened to g=14.0 mag on 2025-11-15. The VSX lists g=21.9 mag as the counterpart, hence the outburst amplitude is ~8 mag. https://vsx.aavso.org/index.php?view=detail.top&oid=10868208 https://asas-sn.osu.edu/sky-patrol/coordinate/579ca10e-176d-4c3b-958f-03a39… Josch Hambsh and Berto Monard have reported the time-resolved observations of ASASSN-25eq. The light curve shows a 1-mag dip around 2025-11-25 UT. After this dip, clear superhumps are present, with a period of ~0.0645 d. There is no clear modulation before the dip. Thus, ASASSN-25eq is a new WZ Sge-type dwarf nova, with a double-superoutburst feature often observed in a period bouncer system. See e.g. https://ui.adsabs.harvard.edu/abs/2018PASJ...70...47K/abstract Given the absence of clear early superhumps, ASASSN-25eq is presumably a face-on system. A spectrum taken with the Mookodi/Lesedi telescope on 16 Nov. is dominated by Balmer absorption lines, which supports this interpretation. 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 31598] TCP J07454958-2442056: most likely a WZ Sge-type dwarf nova
by Yusuke Tampo 15 Dec '25

15 Dec '25

TCP J07454958-2442056: most likely a WZ Sge-type dwarf nova TCP J07454958-2442056 was discovered by Yuji Nakamura on 13th Oct 2025 at 14.0 mag (unfiltered). According to VSX, the outburst amplitude is ~8.2 mag. https://vsx.aavso.org/index.php?view=detail.top&oid=10868099 Josch Hambsch and Sjoerd Dufoer have reported the time-resolved observations of this source. The light curve shows possible superhumps with a period of ~0.055 d, although I cannot conclude due to its faintness and 1-d aliases. Given its large outburst amplitude, almost 40-d outburst duration, and short superhump period, TCP J07454958-2442056 is most likely a new WZ Sge-type dwarf nova. Note that the system has already faded below the detection level of ATLAS. https://fallingstar-data.com/forcedphot/queue/3502597/ 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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