A Seriously Dusty Supernova

In 2010, the supernova SN 2010jl illuminated a corner of a small, irregular galaxy 150 million light-years away. More than a decade later, researchers have found evidence that this collapsing massive star has created a significant amount of cosmic dust.

Superluminous Supernova

SN 2010jl in its host galaxy

This X-ray and optical image shows SN 2010jl in its host galaxy. The supernova is the brightest X-ray source, near the top of the galaxy. [X-ray: NASA/CXC/Royal Military College of Canada/P.Chandra et al); Optical: NASA/STScI]

From high-redshift galaxies to nearby star-forming regions, it’s clear that the universe is a dusty place — but where does all this dust come from? Core-collapse supernovae are one possible source. These cataclysms fling enriched material into interstellar space, where dust grains coalesce out of the cooling ejecta. This is a promising explanation for dust in high-redshift galaxies, which require more rapid dust production than other sources, like evolved low- to intermediate-mass stars, can provide.

SN 2010jl offers an excellent chance to study the dust-forming potential of core-collapse supernovae. This supernova was unusually luminous because of intense interactions between the expanding supernova shock and the dense material surrounding the exploding star, and it’s possible that these types of interactions spur the creation of dust. In the first few years after the supernova was discovered, researchers found evidence that it had produced new dust. What has it been up to since?

SN 2010jl dust mass over time

SN 2010jl’s inferred dust mass over time (black stars) compared to other supernovae. Click to enlarge. [Smith et al. 2026]

Checking Back In

Thirteen years after SN 2010jl was discovered, Nathan Smith (Steward Observatory) and collaborators checked in on its dust production. The team collected new ground-based optical spectra from the Keck I telescope and the MMT Observatory and mid-infrared spectra from JWST. The optical spectra — among the latest collected for any superluminous supernova — show numerous narrow emission lines that indicate that the expanding supernova continues to interact with its surroundings.

In the JWST observations, SN 2010jl is the brightest mid-infrared point source in its host galaxy. Through spectral energy distribution modeling, Smith and coauthors found that the brilliant infrared emission is likely due to a shroud of warm dust totaling roughly 20% of the mass of the Sun. This is about 80 times more dust than inferred from observations made a decade earlier.

Where’s the Dust?

diagram of a supernova's shocks

Diagram showing the outward-moving forward shock and inward-moving reverse shock of a supernova that is interacting with the interstellar medium (ISM). The post-shock region is located between the two shocks and contains shocked ejecta as well as shocked interstellar material. Click to enlarge. [AAS Nova/Kerry Hensley]

While these data appear to tell the tale of a prolific dust-producing supernova, interpreting these results isn’t straightforward — at a distance of 150 million light-years, it’s difficult to pin down the exact location of the dust. If the dust formed in the supernova ejecta that has not yet withstood the passage of the reverse shock, that dust might be destroyed when it passes through the shock. It’s also possible that the emission comes from preexisting dust in the interstellar medium that was destroyed by the passage of the supernova shock, then re-formed as the material cooled. If instead the dust formed in the post-shock region (between the outward-moving forward shock and the inward-moving reverse shock), it should survive and become incorporated into the interstellar medium.

While it’s not possible to rule out the other options entirely, Smith and collaborators argue that at least some of the dust can be traced to new growth in the post-shock region. Because post-shock dust grains are likely to reach the interstellar medium, this suggests that superluminous, strongly interacting supernovae like SN 2010jl are a viable source of dust in the present-day universe and in high-redshift galaxies alike.

Citation

“JWST Spectra Indicate a Large Mass of Postshock Dust Formed by SN 2010jl,” Nathan Smith et al 2026 ApJ 1006 224. doi:10.3847/1538-4357/ae74c5