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

[vsnet-alert 28132] TCP J05384230+7051377: rebrightening
by Hiromasa Hoke 12 Dec '25

12 Dec '25

TCP J05384230+7051377: exhibit rebrightening Itoh-san, Kubotera-san, Tamas Tordai, Alexandra Zubareva, and David Messier have newly reported their observations. According to the data, this object showed a rebrightening, reaching a peak brightness of ~14 mag on 12/11. It was ~10 days to show the rebrightening. WZ Sge-type dwarf nova might exhibit multiple rebrightenings. This object possibly shows more rebrightening. Thus, further snapshots are very welcome. best regard, Hiromasa Hoke

1 0

[vsnet-alert 28131] TCP J05384230+7051377: faded but might show rebrightenings
by Keisuke Isogai 02 Dec '25

02 Dec '25

TCP J05384230+7051377: faded but might show rebrightenings Itoh-san, David Messier, Franky Dubois, Tonny Vanmunster, Sano-san, and Kubotera-san reported their observations. This object showed clear superhumps with an averaged period of 0.06806(1) d. The 0.065 d period in the previous reports was an alias. The object rapidly faded from Nov 29, and now stays around 17.5 mag. The current state is even about 3 mag brighter than in quiescence, and this object might show some rebrightenings. Thus, further snapshots are very welcome.

1 0

[vsnet-alert 28130] ASASSN-25eq: new WZ Sge-type dwarf nova, likely a period bouncer
by Yusuke Tampo 27 Nov '25

27 Nov '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 ----------------------------------------------

1 0

[vsnet-alert 28129] TCP J06364062+3318310: new SU UMa-type dwarf nova
by tonny.vanmunster＠gmail.com 26 Nov '25

26 Nov '25

Dear colleagues, TCP J06364062+3318310 was discovered by K. Sokolovsky et al. (NMW Survey) on 2025 Nov 17.99 at mag 13.6CV. The quiescent counterpart is a 21.3 r mag star, implying an outburst amplitude of ~8 mag. I have just completed the analysis of my unfiltered CCD time-series observations of TCP J06364062+3318310, obtained on 2025 Nov 25/26 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. I also obtained observations on several nights prior to Nov 25/26, but those did not reveal any obvious modulation. In contrast, the Nov 25/26 light curve clearly shows regular superhump modulations with an amplitude of 0.30 mag. A period analysis using ANOVA, Lomb-Scargle, Generalized-Lomb-Scargle and PDM methods (Peranso 3.1) yields a combined superhump period of 0.0661 +/- 0.0008d. The object was measured at mag CV = 15.3 on Nov 26th. Image calibration and photometry were carried out using the latest release of Phoranso, which enabled simultaneous photometry of several additional variable stars in the same field of view. These results establish TCP J06364062+3318310 as a new SU UMa-type dwarf nova. Further follow-up observations are strongly encouraged to refine the superhump period and study its evolution. 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/>

1 0

[vsnet-alert 28120] TCP J05384230+7051377: new WZ Sge-type dwarf nova
by 保家大将 21 Nov '25

21 Nov '25

TCP J05384230+7051377: new WZ Sge-type dwarf nova We posted our spectroscopic follow-up result of TCP J05384230+7051377 to ATel. ATel #17485: Spectroscopic confirmation of TCP J05384230+7051377 as a WZ Sge-type dwarf nova <https://www.astronomerstelegram.org/?read=17485> We concluded that this object 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. Also, we estimated this object as p ~ 0.06d from Itoh-san's data. However p ~ 0.06d is a weak signal, so further observation will provide a more accurate estimate of the period. best regard, Hiromasa Hoke

2 3

[vsnet-alert 28125] TCP J09370380+1657350: possible new superoutburst
by Kojiguchi 19 Nov '25

19 Nov '25

TCP J09370380+1657350: possible new superoutburst Gavin Ramsay reported that GOTO detected TCP J09370380+1657350 in outburst on 2025 Nov 18 03:41:50 UT (20251118.1534). Reported magnitude: L = 16.18 (400–700 nm). This object was previously identified as a WZ Sge-type system. For reference, see also the past report: [vsnet-alert 25216] TCP J09370380+1657350: new WZ Sge-type dwarf nova [vsnet-alert 25218] Spectrum of TCP J09370380+1657350 http://www.astronomerstelegram.org/?read=14309 https://vsx.aavso.org/index.php?view=detail.top&oid=2215274

2 1

[vsnet-alert 28123] TCP J21314718+3825463: new SU UMa-type dwarf nova
by tonny.vanmunster＠gmail.com 15 Nov '25

15 Nov '25

Dear colleagues, TCP J21314718+3825463 was discovered by XOSS (Xingming Observatory Sky Survey) on 2025 Nov 07.6 at mag 14.70C. The quiescent counterpart is a 22.5 g mag star, implying an outburst amplitude of ~8 mag. I have just completed the analysis of my unfiltered CCD observations of TCP J21314718+3825463, obtained on 2025 Nov 11/12 and Nov 14/15 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 Nov 11/12 light curve did not reveal any obvious modulation. However, the Nov 14/15 light curve clearly shows regular superhump modulations with an amplitude of 0.23 mag. A period analysis performed with ANOVA, Lomb-Scargle, Generalized-Lomb-Scargle and PDM methods (Peranso 3.1) yields a combined superhump period of 0.0567 +/- 0.0016d. The object was measured at mag CV = 16.0 on Nov 15th. Image calibration and photometry were carried out using the latest release of Phoranso, which enabled simultaneous photometry of several additional variable stars in the same field of view. These results establish TCP J21314718+3825463 as a new SU UMa-type dwarf nova. Further follow-up observations are strongly encouraged to refine the superhump period and study its evolution. 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/>

1 0

[vsnet-alert 28122] AS 221: a possible symbiotic nova
by Berto Monard 10 Nov '25

10 Nov '25

AS 221 is a symbiotic star system that has recently become significantly brighter. Observations in V and I have been done at the Kleinkaroo Observatory for over 20 resp.10 years with magnitudes evolving in the ranges 15-18V and 12.5-13.5I. The most recent observation was on 2025 Nov 09.76: 13.74V 11.57I. With the observing season nearing the end here, I would like to encourage further observation in V and I from observers at locations that can do so. AS 221: (2000)": 17 12 12.9 -32 37 47 A starchart for photometric reference is attached. Berto Monard / KKO

1 0

[vsnet-alert 28121] TCP J00534786+1617214: new SU UMa-type dwarf nova
by tonny.vanmunster＠gmail.com 10 Nov '25

10 Nov '25

Dear colleagues, TCP J00534786+1617214 (aka ASASSN-25ei) was discovered by Y. Nakamura, Japan on 2025 Nov 1.5 at mag 14.4 U. The quiescent counterpart is a 22.0 g mag star, implying an outburst amplitude of ~7.6 mag. I have just completed the analysis of my unfiltered CCD observations of TCP J00534786+1617214, obtained on 2025 Nov 08/09 at CBA Belgium Observatory. The data were acquired under clear skies with a 0.40-m f/10.0 telescope and a QHY-268M CMOS camera under clear skies. The light curve clearly exhibits regular superhump modulations with an amplitude of 0.19 mag. Period analysis with ANOVA, Lomb-Scargle, Generalized-Lomb-Scargle and PDM methods (Peranso 3.1) yields a combined superhump period of 0.0624 +/- 0.0010d. The object was measured at mag CV = 15.5 on Nov 08th. Image calibration and photometry were performed with the latest release of Phoranso. These results establish TCP J00534786+1617214 as a new SU UMa-type dwarf nova. Follow-up observations are 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 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/>

1 0

[vsnet-alert 28114] 1eRASS J072044.9-402838 = PNV J07204545-4028357 = ASASSN-25ee: new SU UMa-type dwarf nova, likely WZ Sge-type
by Yusuke Tampo 05 Nov '25

05 Nov '25

1eRASS J072044.9-402838 = PNV J07204545-4028357 = ASASSN-25ee: new SU UMa-type dwarf nova, likely WZ Sge-type 1eRASS J072044.9-402838 was originally identified as a CV candidate in Rodriguez et al. (2025), G = 19.2 mag at ~267 pc, hence its absolute magnitude of ~12 mag. https://vsx.aavso.org/index.php?view=detail.top&oid=10868116 https://ui.adsabs.harvard.edu/abs/2025PASP..137a4201R/abstract ASASSN and John Seach discovered its 2025 outburst, peaking at ~11.0 mag around 20th October. https://www.astronomy.ohio-state.edu/asassn/transients.html http://www.cbat.eps.harvard.edu/unconf/followups/J07204545-4028357.html We, the SAAO team, obtained the time-resolved photometries and a snapshot spectrum of 1eRASS J072044.9-402838 on 3rd Nov. The light curve shows likely superhumps with a rough period of ~0.059 d. The spectrum shows Balmer absorption lines from the accretion disk and a superposed narrow emission component in Hα. Hence, 1eRASS J072044.9-402838 is now confirmed as (at least) a SU UMa-type dwarf nova, and probably a WZ Sge-type dwarf nova, considering its large outburst amplitude, long outburst duration, and short superhump period. Further time-resolved observations are encouraged to establish its superhump period and changes. 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 ----------------------------------------------

2 2

2025

2024

2023

2022

2021

vsnet-alert