A 12.4-day periodicity in a close binary system after a supernova

We thank B. Cenko, Y. Levin, E. Pian, S. Dong, D. Lai, O. Yaron, J. Morag, Y. S. Rimalt and T. Shenar for the discussions. We thank D. J. Thompson for his comments. P.C. and A.G.-Y. thank Y. Beletsky for his assistance with Magellan telescope remote observations. This research has made use of the NuSTAR Data Analysis Software (NuSTARDAS) jointly developed by the ASI Space Science Data Center (SSDC) and the California Institute of Technology (Caltech). SED Machine is based on the work supported by the National Science Foundation under grant no. 1106171. This study is based on observations obtained with the 48-inch Samuel Oschin Telescope and the 60-inch Telescope at the Palomar Observatory as part of the Zwicky Transient Facility (ZTF) project. ZTF is supported by the National Science Foundation under grant no. AST-2034437 and a collaboration that includes Caltech, IPAC, the Weizmann Institute of Science, the Oskar Klein Center at Stockholm University, the University of Maryland, Deutsches Elektronen-Synchrotron and Humboldt University, the TANGO Consortium of Taiwan, the University of Wisconsin at Milwaukee, Trinity College Dublin, Lawrence Livermore National Laboratories, IN2P3, University of Warwick, Ruhr University Bochum and Northwestern University. Operations were conducted by COO, IPAC and the University of Wisconsin. The Gordon and Betty Moore Foundation, through both the Data-Driven Investigator Program and a dedicated grant, provided funding for SkyPortal. This work has used data from the ATLAS project. The ATLAS project is primarily funded to search for near-earth asteroids through NASA grant nos NN12AR55G, 80NSSC18K0284 and 80NSSC18K1575; by-products of the NEO search include images and catalogues from the survey area. This work was partially funded by the Kepler/K2 grant J1944/80NSSC19K0112 and HST GO-15889 and STFC grants ST/T000198/1 and ST/S006109/1. The ATLAS science products have been made possible through the contributions of the University of Hawaii Institute for Astronomy, the Queen’s University Belfast, the Space Telescope Science Institute, the South African Astronomical Observatory and the Millennium Institute of Astrophysics (MAS), Chile. This study is based on the observations made with the NOT, owned in collaboration with 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, respectively, 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. One of the spectra from NOT was obtained as part of an NBI school in which M. Killi, N. Allen, K. Gould and D. Zhou participated under the leadership of J. Fynbo. This work was supported by the research project grant Understanding the Dynamic Universe funded by the Knut and Alice Wallenberg Foundation under Dnr KAW 2018.0067. The study is based on the observations collected at the European Organisation for Astronomical Research in the Southern Hemisphere under ESO programme 110.25A6. The access for MMT Observatory for part of the MMT/Binospec data was supported by Northwestern University and the Center for Interdisciplinary Exploration and Research in Astrophysics (CIERA). Mephisto is developed at and operated by the South-Western Institute for Astronomy Research of Yunnan University (SWIFAR-YNU), funded by the Yunnan University Development Plan for World-Class University and Yunnan University Development Plan for World-Class Astronomy Discipline. The Australia Telescope Compact Array is part of the ATNF, which is funded by the Australian government for the operation as a national facility managed by the CSIRO. We acknowledge the Gomeroi people as the Traditional Owners of the Observatory site. The Cosmic Dawn Center (DAWN) is funded by the Danish National Research Foundation under grant no. 140. S. Schulze acknowledges support from the G.R.E.A.T. research environment, funded by Vetenskapsrådet, the Swedish Research Council, project no. 2016-06012. B.Z. is supported by a research grant from the Willner Family Leadership Institute for the Weizmann Institute of Science, a research grant from the Center for New Scientists at the Weizmann Institute of Science and a research grant from the Ruth and Herman Albert Scholarship Program for New Scientists. A.H. acknowledges the support from the I-Core Program of the Planning and Budgeting Committee and the Israel Science Foundation (ISF) and support from the ISF grant no. 647/18. This research was supported by grant no. 2018154 from the United States–Israel Binational Science Foundation (BSF). A.H. is especially grateful to the Sir Zelman Cowen Academic Initiatives for their funding and support. D.L., Xiangkun Liu, Y.F. and Xiaowei Liu acknowledge the support from special grants to the Yunnan Technology Leading Talents and Provincial Innovation Team. D.L., Xiangkun Liu, Y.F. and Xiaowei Liu also acknowledge supports from the Science and Technology Champion Project (202005AB160002) and from two team projects—the Innovation Team (202105AE160021) and the Top Team (202305AT350002)—all funded by the Yunnan Revitalization Talent Support Program. J.P.U.F. is supported by the Independent Research Fund Denmark (DFF-4090-00079) and thanks the Carlsberg Foundation for support.