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TCP J07222683$+$6220548: a new AM CVn type system with infrequent outbursts

Solar and Stellar Astrophysics 2025-12-09 v1

Abstract

We present the discovery of TCP J07222683++6220548, a new ultracompact binary system of the AM CVn type. This system was first identified displaying a ΔV=7.6\Delta V = 7.6 mag outburst on 2025-01-20.9416 UTC by the New Milky Way wide-field survey for transients and later independently detected by ASAS-SN and ZTF. The outburst peaked at Vmax=12.45V_{\rm max} = 12.45 and lasted for seven days, followed by a series of rebrightenings. No previous outbursts are found in archival data. Positive superhumps with a period of 0.032546±0.0000840.032546 \pm 0.000084 d (46.87±0.1246.87 \pm 0.12 min), barely detectable during the main outburst, became clearly visible during the first rebrightening that lasted from day 18 to day 24 after the initial outburst. No convincing change in the superhump period was detected. Dense time-series photometry follow-up by a pair of 0.5-m INASAN robotic telescopes, together with VSNET and AAVSO observers, was essential for identifying TCP J07222683++6220548 as an AM CVn system and triggering confirmation spectroscopy with the 2.5-m CMO SAI telescope. Some outbursting AM CVn systems lacking such detailed follow-up may remain unrecognized among the newly discovered cataclysmic variable candidates.

Keywords

Cite

@article{arxiv.2505.20842,
  title  = {TCP J07222683$+$6220548: a new AM CVn type system with infrequent outbursts},
  author = {Alexander Tarasenkov and Kirill Sokolovsky and Alexandr Dodin and Oxana Chernyshenko and Stanislav Korotkiy and Ivan Strakhov and Marina Burlak and Sergey Naroenkov and Franz-Josef Hambsch and Tamás Tordai and Hiroshi Itoh and Yasuo Sano and Yusuke Tampo and Ferdinand},
  journal= {arXiv preprint arXiv:2505.20842},
  year   = {2025}
}

Comments

Accepted for publication in Research in Astronomy and Astrophysics