THE BOLOMETRIC LIGHT-CURVE OF SN-1987A .1. RESULTS FROM ESO AND CTIO U TO Q0 PHOTOMETRY

Ultraviolet, optical, and infrared (uvoir) photometry of SN 1987A, representing the supernova flux from 0.32 to 20 μm, is used to construct the bolometric light curve for days 1-903 since outburst. SN 1987A has declined exponentially with an e-folding time of 100 ± 5 days from day 126 to day 903. The sum of the uvoir flux and the high-energy flux of the gamma-ray lines and x-ray continuum from model fits is consistent with the energy released by 0.055-0.090 script M sign⊙ of 56Co. No additional energy source greater than 1.5 × 1038 ergs s-1 on day 900 is present. By day 400, the flux at wavelengths larger than 5 μm began to increase rapidly, and by day 650, it represented 80% of the uvoir flux. After day 600, the far-infrared source can be fit with a blackbody of temperature 200-400 K. The optical colors began to fade more rapidly at the time the far-infrared flux increased, consistent with dust formation local to the supernova. No more than 30% of the far-infrared flux can be due to thermal re-radiation of energy in a cloud behind SN 1987A along the line of sight (the "infrared echo") without violating the energy budget of SN 1987A, or requiring a larger fraction of high-energy photons to escape than are predicted by the models. The effective angular radius of the thermal component is ∼0.015″ after day 600, which is consistent with the velocity of the emitting ejecta.