Serendipitous detection of the dusty Type IIL SN 1980K with <i>JWST</i>/MIRI
Szanna Zsíros, Tamás Szalai, Ilse De Looze, Arkaprabha Sarangi, Melissa Shahbandeh, Ori D. Fox, Tea Temim, D. Milisavljević, Schuyler D. Van Dyk, Nathan Smith, A. V. Filippenko, Thomas G. Brink, WeiKang Zheng, Luc Dessart, J. Jencson, J. Johansson, Justin Pierel, A. Rest, Samaporn Tinyanont, Maria Niculescu-Duvaz, M. J. Barlow, R. Wesson, Jennifer E. Andrews, Geoffrey C. Clayton, Kishalay De, E. Dwek, Michael Engesser, R. J. Foley, Suvi Gezari, Sebastián Gómez, S. Gonzaga, M. M. Kasliwal, Ryan M. Lau, A. P. Marston, Richard O’Steen, M. R. Siebert, Michael F. Skrutskie, Lou Strolger, Qinan Wang, Brian P. Williams, Robert Williams, Lin Xiao
Abstract
ABSTRACT We present mid-infrared (mid-IR) imaging of the Type IIL supernova (SN) 1980K with the JWST more than 40 yr post-explosion. SN 1980K, located in the nearby (D ≈ 7 Mpc) ‘SN factory’ galaxy NGC 6946, was serendipitously captured in JWST/MIRI images taken of the field of SN 2004et in the same galaxy. SN 1980K serves as a promising candidate for studying the transitional phase between young SNe and older SN remnants and also provides a great opportunity to investigate its the close environment. SN 1980K can be identified as a clear and bright point source in all eight MIRI filters from F560W up to F2550W. We fit analytical dust models to the mid-IR spectral energy distribution that reveal a large amount (Md ≈ 0.002 M⊙) of Si-dominated dust at $T_\rm {dust}\approx 150$ K (accompanied by a hotter dust/gas component), and also computed numerical SED dust models. Radiative transfer modelling of a late-time optical spectrum obtained recently with Keck discloses that an even larger (∼0.24–0.58 M⊙) amount of dust is needed in order for selective extinction to explain the asymmetric line profile shapes observed in SN 1980K. As a conclusion, with JWST, we may see i) pre-existing circumstellar dust heated collisionally (or, partly radiatively), analogous to the equatorial ring of SN 1987A, or ii) the mid-IR component of the presumed newly-formed dust, accompanied by much more colder dust present in the ejecta (as suggested by the late-time the optical spectra).