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-03a39d...
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
ASASSN-25eq: rebrightening
ASASSN detected its rebrigheing on 2025-12-17 UT at around 15.3 mag. https://asas-sn.osu.edu/sky-patrol/coordinate/c87c69a6-108f-4280-ab5a-38e641... Continuous monitoring may reveal further rebrighenings.
Best regards, Yusuke
2025年11月27日(木) 10:28 Yusuke Tampo tampo@kusastro.kyoto-u.ac.jp:
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-03a39d...
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@kusastro.kyoto-u.ac.jp ALT. EMAIL: yusuke@saao.ac.za
vsnet-alert@ooruri.kusastro.kyoto-u.ac.jp
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Yusuke Tampo