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arXiv · 2202.11832

Analysis of the IW And star ASAS J071404+7004.3

Taichi Kato·Kiyoshi Kasai·Elena P. Pavlenko·Nikolaj V. Pit·Aleksei A. Sosnovskij·Hiroshi Itoh·Hidehiko Akazawa·Stephen M. Brincat·Leonid E. Keir·Sergei N. Udovichenko·Yusuke Tampo·Naoto Kojiguchi·Masaaki Shibata·Yasuyuki Wakamatsu·Tamas Tordai·Tonny Vanmunster·Charles Galdies
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Abstract

We made a time-resolved photometric campaign of the bright cataclysmic variable ASAS J071404+7004.3 in 2020. Inight et al. (2022, arXiv/2109.14514) recently published time-resolved optical spectroscopy, X-ray observations and long- and short-term optical variations. Although their results were correct in many parts, they classified ASAS J071404+7004.3 as a VY Scl-type novalike object. By comparing the ASAS-SN data of this object and the IW And-type object HO Pup, we showed that their type classification was incorrect. ASAS J071404+7004.3 showed outbursts from a standstill followed by shallow dips, which is the defining characteristic of an IW And star. This object predominantly showed states with low-amplitude dwarf nova-type oscillations, some of which could be identified as the "heartbeat"-type state as a variety of the IW And-type phenomenon. The low state described by Inight et al. (2022) was not a true low state of a VY Scl star, but a dwarf nova-type state with increased outburst amplitudes. Both ground-based (our campaign) and TESS observations detected orbital variations whose periods [0.136589(5) d by the ground-based campaign and 0.1366476(3) d by the TESS data] are in very good agreement with the one obtained by radial-velocity studies by Inight et al. (2022). The standstill in 2019-2020 in ASAS J071404+7004.3 was not brighter than its dwarf nova-type states. The brightest moment of this object occurred when the amplitudes of dwarf nova-type variations were large, which challenges the widely accepted interpretation that standstills in Z Cam stars occur when the mass-transfer rates are high.

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Taichi Kato, Kiyoshi Kasai, Elena P. Pavlenko, Nikolaj V. Pit, Aleksei A. Sosnovskij, Hiroshi Itoh, Hidehiko Akazawa, Stephen M. Brincat, Leonid E. Keir, Sergei N. Udovichenko, Yusuke Tampo, Naoto Kojiguchi, Masaaki Shibata, Yasuyuki Wakamatsu, Tamas Tordai, Tonny Vanmunster, Charles Galdies. 2022-02-23. Analysis of the IW And star ASAS J071404+7004.3. https://arxiv.org/abs/2202.11832

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