JWST/MIRI detects the dusty SN1993J about 30 years after explosion

¹ Department of Experimental Physics, Institute of Physics, University of Szeged, Dóm tér 9, 6720 Szeged, Hungary
² MTA-ELTE Lendület “Momentum” Milky Way Research Group, Szent Imre H. st. 112, 9700 Szombathely, Hungary
³ Department of Physics and Astronomy, Johns Hopkins University, Baltimore, MD 21218, USA
⁴ Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218, USA
⁵ DARK, Niels Bohr Institute, University of Copenhagen, Jagtvej 128, 2200 Copenhagen, Denmark
⁶ Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544, USA
⁷ Sterrenkundig Observatorium, Ghent University, Krijgslaan 281 – S9, 9000 Gent, Belgium
⁸ Steward Observatory, University of Arizona, 933 N. Cherry St, Tucson, AZ 85721, USA
⁹ Department of Astronomy, University of California, Berkeley, CA 94720-3411, USA
¹⁰ Caltech/IPAC, Mailcode 100-22, Pasadena, CA 91125, USA
¹¹ Gemini Observatory, 670 N. Aohoku Place, Hilo, Hawaii 96720, USA
¹² Department of Physics, Virginia Tech, Blacksburg, VA 24061, USA
¹³ Department of Physics & Astronomy, Louisiana State University, Baton Rouge, LA 70803, USA
¹⁴ Institut d’Astrophysique de Paris, CNRS–Sorbonne Université, 98 bis boulevard Arago, F-75014 Paris, France
¹⁵ NASA at Goddard Space Flight Center, Code 665, Greenbelt, MD 20771, USA
¹⁶ Center for Astrophysics | Harvard & Smithsonian, 60 Garden Street, Cambridge, MA 02138-1516, USA
¹⁷ Oskar Klein Centre, Department of Physics, Stockholm University, AlbaNova, SE-10691 Stockholm, Sweden
¹⁸ Purdue University, Department of Physics and Astronomy, 525 Northwestern Ave, West Lafayette, IN 47907, USA
¹⁹ Integrative Data Science Initiative, Purdue University, West Lafayette, IN 47907, USA
²⁰ Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064, USA
²¹ National Astronomical Research Institute of Thailand, 260 Moo 4, Donkaew, Maerim, Chiang Mai 50180, Thailand
²² MIT-Kavli Institute for Astrophysics and Space Research, 77 Massachusetts Ave., Cambridge, MA 02139, USA
²³ Cahill Center for Astrophysics, California Institute of Technology, 1200 E. California Blvd., Pasadena, CA 91125, USA
²⁴ NSF’s NOIRLab, 950 N. Cherry Avenue, Tucson, 85719 AZ, USA
²⁵ European Space Agency (ESA), ESAC, 28692 Villanueva de la Canada, Madrid, Spain
²⁶ Department of Astronomy, University of Virginia, Charlottesville, VA 22904-4325, USA
²⁷ X-ray Astrophysics Laboratory, NASA/Goddard Space Flight Center (GSFC), Greenbelt, MD 20771, USA
²⁸ Department of Physics, College of Physical Sciences and Technology, Hebei University, Wusidong Road 180, Baoding 071002, China
²⁹ Department of Physics, College of Physical Sciences and Technology, Hebei University, Wusidong Road 180, Baoding 071002, China

^⋆ Corresponding author: szaszi@titan.physx.u-szeged.hu

Received: 11 July 2024
Accepted: 12 March 2025

Abstract

Context. Core-collapse supernovae (CCSNe) have long been considered to contribute significantly to the cosmic dust budget. Newly-formed dust in the SN ejecta cools quickly and is therefore detectable at mid-infrared (mid-IR) wavelengths. However, before the era of the James Webb Space Telescope (JWST), direct observational evidence for dust condensation was found in only a handful of nearby CCSNe, and dust masses (∼10⁻² − 10⁻³ M_⊙, generally limited to < 5 yr and to > 500 K temperatures) have been two to three orders of magnitude smaller than theoretical predictions and dust amounts found by far-IR/submillimeter observations of Galactic SN remnants and in the very nearby SN 1987A.

Aims. As recently demonstrated, the combined angular resolution and mid-IR sensitivity of JWST finally allow hidden cool (∼100–200 K) dust reservoirs in extragalactic SNe beyond SN 1987A to be revealed. Our team received JWST/MIRI time for studying a larger sample of CCSNe to fill the currently existing gap in their dust formation histories. The first observed target of this program was the well-known Type IIb SN 1993J that appeared in M81.

Methods. We generated its spectral energy distribution (SED) from the current JWST/MIRI F770W, F1000W, F1500W, and F2100W fluxes. We fit single- and two-component silicate and carbonaceous dust models to the SED in order to determine the dust parameters.

Results. We find that SN 1993J still contains a significant amount (∼0.01 M_⊙) of dust ∼30 yr after explosion. Comparing our results to those from the analysis of earlier Spitzer Space Telescope data, we observed a similar amount of dust as was detected ∼15–20 yr ago, but at a lower temperature (noting that the modeling results of the earlier Spitzer SEDs have strong limitations). We also found residual background emission near the SN site (after point-spread-function subtraction on the JWST/MIRI images) that may plausibly be attributed to an IR echo from more distant interstellar dust grains heated by the SN shock-breakout luminosity or ongoing star formation in the local environment.