Precursor Activity Preceding Interacting Supernovae I: Bridging the Gap with SN 2022mop
Abstract
Over the past two decades, an increasing number of transients have shown luminous activity at their explosion sites weeks to years before an interacting supernova (SN) is observed. For some objects, this pre-SN activity is typically linked to large-scale mass-loss events preceding core collapse, yet its triggering mechanism and the underlying explosion process remain uncertain. We present SN 2022mop, which was initially observed in August 2022, exhibiting nebular emission, including [O I], Mg I], and [Ca II], resembling the late-time (~200 days post-explosion) spectrum of a stripped-envelope SN (SESN) from a progenitor with M[ZAMS] < 18 Msun. SN 2022mop shows strong (~ 1 mag) repeating undulations in its light curve, suggesting late-time interaction. In mid-2024, the transient re-brightened for several months before a Type IIn SN (r[peak] = -18.2 mag) was observed in December 2024, closely resembling the evolution of SN 2009ip. By triangulating both transients using Pan-STARRS images, we determine that both transients are coincident within approximately 3 parsecs. Given the environment, the chance alignment of two isolated SNe is unlikely. We propose a merger-burst scenario: a compact object formed in 2022, is kicked into an eccentric orbit, interacts with its hydrogen-rich companion over subsequent months, and ultimately merges, triggering a Type IIn SN-like transient.
Keywords
Cite
@article{arxiv.2503.08768,
title = {Precursor Activity Preceding Interacting Supernovae I: Bridging the Gap with SN 2022mop},
author = {S. J. Brennan and S. Barmentloo and S. Schulze and K. W. Smith and R. Hirai and J. J. Eldridge and M. Fraser and H. F. Stevance and S. J. Smartt and S. Anand and A. Aryan and T. -W. Chen and K. K. Das and A. J. Drake and C. Fransson and A. Gangopadhyay and A. Gkini and W. V. Jacobson-Galán and A. Jerkstrand and J. Johansson and M. Nicholl and G. Pignata and N. Sarin and A. Singh and J. Sollerman and S. Srivastav and B. F. A. van Baal and K. C. Chambers and M. W. Coughlin and H. Gao and M. J. Graham and M. E. Huber and C. -C. Lin and T. B. Lowe and E. A. Magnier and F. J. Masci and J. Purdum and A. Rest and B. Rusholme and R. Smith and I. A. Smith and J. W. Tweddle and R. J. Wainscoat and T. de Boer},
journal= {arXiv preprint arXiv:2503.08768},
year = {2025}
}
Comments
Submitted to A&A. 17 pages, 16 figures, and 3 tables. Data will be uploaded to WISeREP upon acceptance