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=10868208https://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
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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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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/>
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/>
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/>
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=10868116https://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.htmlhttp://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
--
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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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TCP J05415572-2308340: new WZ Sge-type dwarf nova
The NMW survey discovered TCP J05415572-2308340 at 13.2 mag on 16 Oct.
The counterpart is Gaia EDR3 2963574610161432960 G= 20.65(1) mag.
https://vsx.aavso.org/index.php?view=detail.top&oid=10868112http://www.cbat.eps.harvard.edu/unconf/followups/J05415572-2308340.html
Josch Hambsh and Itoh-san have reported the time-resolved observations
of TCP J05415572-2308340. After 23 Oct 2025, this shows the
single-peaked superhumps with a mean period of 0.05496(2) d and an
amplitude of 0.08 mag. Before this epoch, there were no clear
modulations.
Thus, this long waiting time before the appearance of ordinary
superhumps, together with a large outburst amplitude and long outburst
duration, suggests that TCP J05415572-2308340 is a new WZ Sge-type
dwarf nova.
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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