Black: observed main-beam temperature as a function of velocity for 16 rotational transitions of SiO (see Table 1). The telescope and rotational quantum numbers are indicated for each line. Red: resulting line profiles using an abundance profile characterised by f₀ = 6.0 × 10^-5 relative to H₂ and e-folding radius r_e = 4 × 10¹³ cm with R_decl = 50 R_∗. The υ_LSR of R Dor is 7.5 km s^-1.