Molecules, Dust and Ionic Abundances in SN 1987A

Abstract

The continuing evolution of SN 1987A has brought new developments even if some of them had been predicted at various epochs in the near or distant past. Formation of molecules, CO and SiO, in the expanding envelope at a very early stage focussed some attention on the possibility of subsequent formation of dust. From observations made at ESO, La Silla, irrefutable evidence for the formation of dust near day 530 will be presented together with other spectroscopic and photometric data that seem to be associated with this event. This qualitative interpretation will be elaborated more fully in a quantitative treatment by Lucy et al. [1]. Some observational data concerning the strength and temporal behaviour of the vibration-rotation bands of CO is discussed because theoretical attempts to define the molecular chemistry are now appearing.