Fig. 2. Spectral energy distribution of MIR1, constructed from optical photometry and ISO data (Table 1). Error bars of the mid-IR data are formal IRAF/APPHOT errors. Solid line shows two-blackbody fit to the optical and mid-IR data ( K and K); dashed line indicates K fit to the mid-IR ISOCAM data used to estimate the infrared luminosity (see text for details).