Silicon carbide dust grains are ubiquitous in circumstellar envelopes aroundC-rich AGB stars. However, the main gas-phase precursors leading to theformation of SiC dust have not yet been identified. To date, only threemolecules containing an Si--C bond have been identified to have significantabundances in C-rich AGB stars: SiC$_2$, SiC, and Si$_2$C. The ring moleculeSiC$_2$ has been observed in a handful of evolved stars, while SiC and Si$_2$Chave only been detected in the C-star envelope IRC +10216. We aim to study howwidespread and abundant SiC$_2$, SiC, and Si$_2$C are in envelopes aroundC-rich AGB stars and whether or not these species play an active role asgas-phase precursors of silicon carbide dust in the ejecta of carbon stars.
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