Using the Gemini South 8m telescope , we obtained high resolution 11.7 and 18.3 \mu m mid-IR images of SN 1987A on day 6526 since the explosion .
All the emission arises from the equatorial ring .
Nearly contemporaneous spectra obtained at 5–38 \mu m with the Spitzer Space Telescope show that this is thermal emission from silicate dust that condensed out in the red giant wind of the progenitor star .
The dust temperature is 166 ^ { +18 } _ { -12 } K , and the emitting dust mass is ( 2.6 ^ { +2.0 } _ { -1.4 } ) \times 10 ^ { -6 } M _ { \odot } .
Comparison of the Gemini 11.7 \mu m image with Chandra X-ray images , Hubble UV- optical images , and ATCA radio synchrotron images shows generally good correlation across all wavelengths .
If the dust resides in the diffuse X-ray emitting gas then it is collisionally heated .
The IR emission can then be used to derive the plasma temperature and density , which were found to be in good agreement with those inferred from the X-rays .
Alternatively , the dust could reside in the dense UV-optical knots and be heated by the radiative shocks that are propagating through the knots .
In either case the dust-to-gas mass ratio in the CSM around the supernova is significantly lower than that in the general interstellar medium of the LMC , suggesting either a low condensation efficiency in the wind of the progenitor star , or the efficient destruction of the dust by the SN blast wave .
Overall , we are witnessing the interaction of the SN blast wave with its surrounding medium , creating an environment that is rapidly evolving at all wavelengths .