Dusty supernovae (MIRI)

Images from the NASA/ESA/CSA James Webb Space Telescope’s MIRI (Mid-Infrared Instrument) reveal large amounts of dust from two Type II supernovae, Supernova 2004et (SN2004 et) and Supernova 2017eaw (SN 2017eaw), located 22 million light-years away from Earth in spiral galaxy NGC 6946. The large amounts of dust found around these supernovae support the theory that supernovae played a key role in supplying dust to the early Universe.

SN 2004et is highlighted in the left panel of this image, and SN 2017eaw in the right panel. Webb’s exquisite sensitivity and capability to observe in the mid-infrared allow it to detect the cooler dust that survived the internal shocks reverberating in the aftermath of the dying stars’ explosions. In these images, the bluer colours indicate hotter dust, while red is cooler dust. The hexagonal shape of SN 2004et in Webb’s image is an artefact of the telescope’s mirror and struts — when the bright light of a point source is observed, the light interacts with the sharp edges of the telescope, creating diffraction spikes.

The new Webb discovery is the first breakthrough in the study of dust production from supernovae since the detection of newly formed dust in relatively nearby (170,000 light-years) Supernova 1987A.

In SN 2004et, researchers using Webb found more than 5,000 Earth masses of dust, rivalling the amount of dust found in SN 1987A. That’s why SN 2004et appears brighter and redder in Webb images. SN 2017eaw is currently hotter, with less dust (bluer in Webb observations), but in 13 years, researchers expect it to appear similar to how SN 2004et does now.

In these images, blue, green, and red were assigned to Webb’s MIRI data at 10; 11.3, 12.8, and 15; and 18 and 21 microns (F1000W; F1130W, F1280W, and F1500W; and F1800W and F2100W, respectively).

SN 2004et and SN2017eaw are the first of five targets included in this program. The observations were completed as part of Webb General Observer program 2666. The paper was published in the Monthly Notices of the Royal Astronomical Society on 5 July.

MIRI was developed as a partnership between Europe and the USA: the main partners are ESA, a consortium of nationally funded European institutes, the Jet Propulsion Laboratory (JPL), and the University of Arizona. The instrument was nationally funded by the European Consortium under the auspices of the European Space Agency. The principal investigator leading the MIRI European Consortium is Gillian Wright (UK Astronomy Technology Centre) and the MIRI American science lead is George Rieke (University of Arizona).

[Image description: An image is split down the middle. At the top right of each half is a box with a zoomed-in image, connected by lines to a smaller area of the main image. On the left side, the large white box is labelled SN 2004et. In this larger box is a zoomed-in image of a dot on the larger main image. On the right side, the large white box is labelled SN 2017eaw. The zoomed-in image is a small light blue dot. The main images on each side are mostly black sections of a galaxy, with various smatterings of white dust clumps, small red dots, and light blue dots.]

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