We present high spatial resolution LBTI/NOMIC 9–12 \micron images of VY CMa and its massive outflow feature , the Southwest ( SW ) Clump .
Combined with high-resolution imaging from HST ( 0.4–1 \micron ) and LBT/LMIRCam ( 1–5 \micron ) , we isolate the spectral energy distribution ( SED ) of the clump from the star itself .
Using radiative-transfer code DUSTY , we model both the scattered light from VY CMa and the thermal emission from the dust in the clump to estimate the optical depth , mass , and temperature of the SW Clump .
The SW Clump is optically thick at 8.9 \micron with a brightness temperature of \sim 200 K. With a dust chemistry of equal parts silicates and metallic iron , as well as assumptions on grain size distribution , we estimate a dust mass of 5.4 \times 10 ^ { -5 } M _ { \odot } .
For a gas–to–dust ratio of 100 , this implies a total mass of 5.4 \times 10 ^ { -3 } M _ { \odot } .
Compared to the typical mass-loss rate of VY CMa , the SW Clump represents an extreme , localized mass-loss event from \lesssim 300 years ago .