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We present mid- and far- IR imaging of four famous hypergiant stars: the redsupergiants $\mu$ Cep and VY CMa, and the warm hypergiants IRC +10420 and$\rho$ Cas. Our 11 to 37 $\mu$m SOFIA/FORCAST imaging probes cool dust notdetected in visual and near-IR imaging studies. Adaptive optics (AO) 8 - 12$\mu$m imaging of $\mu$ Cep and IRC +10420 with MMT/MIRAC reveals extendedenvelopes that are the likely sources of these stars' strong silicate emissionfeatures. We find $\mu$ Cep's mass-loss rate to have declined by about a factorof 5 over a 13,000 history, ranging from 5 $\times$ 10$^{-6}$ down to $\sim$1$\times$ 10$^{-6}$ $M_{\odot}$ yr$^{-1}$. The morphology of VY CMa indicates acooler dust component coincident with the highly asymmetric reflection nebulaeseen in the visual and near-IR. The lack of cold dust at greater distancesaround VY CMa indicates its mass-loss history is limited to the last $\sim$1200years, with an average rate of 6 $\times$ 10$^{-4}$ $M_{\odot}$ yr$^{-1}$. Wefind two distinct periods in the mass-loss history of IRC +10420 with a highrate of 2 $\times$ 10$^{-3}$ $M_{\odot}$ yr$^{-1}$ until approximately 2000 yrago, followed by an order of magnitude decrease in the recent past. Weinterpret this change as evidence of its evolution beyond the RSG stage. Ournew infrared photometry of $\rho$ Cas is consistent with emission from theexpanding dust shell ejected in its 1946 eruption, with no evidence of newerdust formation from its more recent events.

Searching for Cool Dust in the Mid-to-Far Infrared: the Mass Loss Histories of The Hypergiants $\mu$ Cep, VY CMa, IRC+10420, and $\rho$ Cas