Silicon monoxide in Supernova 1987A

Abstract

The 8.1-μm Δv = 1 emission band of silicon monoxide detected in SN1987A is modelled. Near day 500 the SiO mass is 4±2×10-6 M and the excitation temperature is ∼ 1500 K. The mass of SiO is about 10 per cent of the mass of dust inferred from the mid-infrared emission near day 600, while the temperature is close to the condensation temperature of silicate grains. The SiO molecules may have been precursors to dust grain formation.