Measured spectral energy distribution, and SED of the best-fitting double-dust belt model (green: hot ring, red: warm belt, blue: total). Top panel: global SED including a NextGen photosphere model (solid black line), bottom panel: circumstellar excess emission. From left to right, thick squares denote the VLTI/VINCI 2.18 μm excess, MIPS 24 μm and Herschel/PACS 70 μm photometry with 1σ error bars. Spitzer/IRS spectrum (grey crosses, not fitted) and ALMA 870 μm photometry (purple cross) are shown as 3σ upper limits.