EP250108a/SN 2025kg: A Jet-driven Stellar Explosion Interacting with Circumstellar Material

Abstract

Copyright and License

© 2025. The Author(s). Published by the American Astronomical Society.  Original content from this work may be used under the terms of the Creative Commons Attribution 4.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI.

Acknowledgement

G.P.S. thanks Jillian Rastinejad and Rob Eyles-Ferris for useful discussions about the nature of this source. G.P.S. thanks Kaustav K. Das for useful insight about the relationship between the peaks in double-peaked SNe. G.P.S. thanks Simi Bhullar for her moral support during the paper writing process. B.O. is supported by the McWilliams Fellowship at Carnegie Mellon University. K.M. acknowledges support from JSPS KAKENHI grants JP24KK0070 and JP24H01810 and the JSPS Bilateral Joint Research Project (JPJSBP120229923). H.K. was funded by the Research Council of Finland projects 324504, 328898, and 353019. G.P.S. thanks Ehud Nakar for useful discussions regarding the interpretaion of this source.

The observations by Gemini-S (S24B-041, GS-2024B-Q-101, GS-2024B-Q-102; PI: K. Maeda) were carried out within the framework of the Subaru-Keck/Subaru-Gemini time exchange program, which is operated by the National Astronomical Observatory of Japan. We are honored and grateful for the opportunity of observing the Universe from Maunakea, which has cultural, historical, and natural significance in Hawaii. The Liverpool Telescope is operated on the island of La Palma by Liverpool John Moores University in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofisica de Canarias with financial support from the UK Science and Technology Facilities Council. Some of the data presented herein were obtained at the W.M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California, and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W.M. Keck Foundation. The authors wish to recognize and acknowledge the very significant cultural role and reverence that the summit of Maunakea has always had within the indigenous Hawaiian community. We are most fortunate to have the opportunity to conduct observations from this mountain. Observations reported here were obtained at the MMT Observatory, a joint facility of the Smithsonian Institution and the University of Arizona. This work was also based on observations made with the Nordic Optical Telescope, owned in collaboration by the University of Turku and Aarhus University and operated jointly by Aarhus University, the University of Turku, and the University of Oslo, representing Denmark, Finland, and Norway, and the University of Iceland and Stockholm University at the Observatorio del Roque de los Muchachos, La Palma, Spain, of the Instituto de Astrofisica de Canarias. This work makes use of observations from the Las Cumbres Observatory global telescope network. Based on observations obtained at the SOAR telescope, which is a joint project of the Ministério da Ciência, Tecnologia e Inovações (MCTI/LNA) do Brasil, the US National Science Foundation’s NOIRLab, the University of North Carolina at Chapel Hill (UNC), and Michigan State University (MSU). The National Radio Astronomy Observatory and Green Bank Observatory are facilities of the US National Science Foundation operated under cooperative agreement by Associated Universities, Inc. The material is based upon work supported by NASA under award number 80GSFC24M0006.