Re: TCP J16271026-1030020: confirmation as a WZ Sge-type dwarf nova
SAAO Lesedi telescope, Josch Hambsh, Itoh-san, Tonny Vanmunster, and Berto Monard have reported the time-resolved observations of TCP J16271026-1030020 so far. The PDM analysis using data before 2025-07-31 detects a double-peak variation with a period of 0.06389(1) d and a mean amplitude of ~0.07 mag, confirming early superhumps and its WZ Sge-type nature. Currently, it does not show any clear modulations, and the appearance of ordinary superhumps is expected within a few days.
Best regards, Yusuke
2025年7月26日(土) 10:02 Yusuke Tampo tampo@kusastro.kyoto-u.ac.jp:
TCP J16271026-1030020: a new WZ Sge-type dwarf nova candidate possibly with large-amplitude early superhump
TCP J16271026-1030020 was discovered by T. Kojima on 2025-07-25.52 UTC at 13.8 mag (unfiltered). ATLAS force photometry and ASASSN also detect this outburst since 2025-07-22.3 UTC, peaking around g~12.6 mag. The Pan-STARRS1 counterpart is g=22.1(2) mag, giving the outburst amplitude of ~9.5 mag. http://www.cbat.eps.harvard.edu/unconf/followups/J16271026-1030020.html https://vsx.aavso.org/index.php?view=detail.top&oid=10867693
I have obtained the low-resolution spectrum with the Lesedi telescope at the SAAO Sutherland. This spectrum shows prominent Balmer, He II 4686, and other He I emission lines with no absorption features. Itoh-san also reported the time-resolved observations for ~45 min. The light curve shows a modulation of ~0.2 mag. These overall features suggest that TCP J16271026-1030020 is a new large-amplitude dwarf nova, most likely a WZ Sge-type, showing relatively large early superhump amplitude.
Further time-resolved observations (with multiple bands, if possible) and time-resolved spectroscopy 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