TCP J04272195-2528038; rapid decline

Itoh-san, Josch Hambsch, and myself using the SAAO/Lesedi have reported the further time-resolved observations of this system. Funada-san and Moriyama-san have reported snapshots as well.

TCP J04272195-2528038 is now undergoing the rapid decline since 16th Jan, currently around 17.5 mag. Such a dip in the middle of an outburst is typical for superoutbursts in AM CVn stars.

Daily snapshots are still encouraged to detect its recovery from the dip. Once it gets back to the bright state, time-resolved observations would be encouraged to detect ordinary superhumps and confirm its classification.

Best regards, Yusuke

2025年1月11日(土) 14:43 Yusuke Tampo tampo@kusastro.kyoto-u.ac.jp:

TCP J04272195-2528038; possibly a new AM CVn star in outburst?

TCP J04272195-2528038 was discovered by Y. Nakamura on 2025-01-09.4837 UT at 14.2 mag. The quiescence counterpart is g_PS1=21.09(5) mag, thus outburst amplitude is ~7 mag. http://www.cbat.eps.harvard.edu/unconf/followups/J04272195-2528038.html https://www.aavso.org/vsx/index.php?view=detail.top&oid=2391199

Itoh-san and myself using the SAAO/Lesedi telescope have reported the time-resolved observations. The SAAO data shows a possible double-peaked modulation with a period of ~42.6 min. In addition, the optical spectrum I obtained with the 1.9m telescope at the SAAO shows only the He I absorption lines, lacking any significant Balmer emission/absorption lines.

Further observations are encouraged to establish its classification and determine the variation period.

Best regards, Yusuke

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South African Astronomical Observatory, Postdoc fellow 反保 雄介 Yusuke TAMPO MAIL: tampo@kusastro.kyoto-u.ac.jp MAIL: yusuke@saao.ac.za

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