Abstract:
The equivalent width of R₁ (16) line of the 0-0 band of the Swan system of C₂ calculated for the minimum phase of light variation in η Aql comes out to be 27 mÅ. Thus, if Dawe’s model atmosphere and the assumed abundance are realistic, the lines belonging to the 0-0 band of Swan system of C₂ will be observable in the η Aql spectrum.