1999A&A...347..500L

We report on observations of SN 1987A with ISO SWS/LWS made 9-11 years after the explosion. No emission from the supernova was seen. In particular, the upper limits on the fluxes of [Fe I] 24.05µm and [Fe II] 25.99µm on day 3999 are ∼1.1Jy and ∼1.4Jy, respectively. Assuming a homogeneous distribution of ⁴⁴Ti inside 2000km/s, we have made theoretical models to estimate the mass of ejected ⁴⁴Ti. Assessing various uncertainties of the model, we obtain an upper limit of ≃1.5x10^–4M_☉. The implications of this are discussed. The LWS data display continuum emission as well as nebular lines of [O I], [C II] and [O III] from neighboring photoexcited regions in the LMC. The [O III] lines indicate an electron density of 120±75cm^–3, and the continuum can be explained by dust with a temperature of ∼37K. A second dust component with ∼10K may also be present.