2021ApJ...917...84D

SN 2010jl is a Type IIn core-collapse supernova whose radiative output is powered by the interaction of the supernova (SN) shock wave with its surrounding dense circumstellar medium (CSM). After day ∼60, its light curve developed a near-infrared (NIR) excess emission from dust. This excess could be a thermal IR echo from preexisting CSM dust, or emission from newly formed dust either in the cooling post-shock region of the CSM, or in the cooling SN ejecta. Recent analysis has shown that dust formation in the CSM can commence only after day ∼380, and has also ruled out newly formed ejecta dust as the source of the NIR emission. The early (<380 days) NIR emission can therefore only be attributed to an IR echo. The H-K color temperature of the echo is about 1250 K. The best-fitting model requires the presence of about 1.6 x 10^–4 M_☉ of amorphous carbon dust at a distance of 2.2 x 10¹⁶ cm from the explosion. The CSM-powered luminosity is preceded by an intense burst of hard radiation generated by the breakout of the SN shock through the stellar surface. The peak burst luminosity seen by the CSM dust is significantly reduced by Thomson scattering in the CSM, but still has the potential of evaporating the dust needed to produce the echo. We show that the survival of the echo-producing dust provides important constraints on the intensity, effective temperature, and duration of the burst.