Granulation on a quiet K dwarf: HD 166620 I. Spectral signatures as a function of line-formation temperature. - Anna John, A; Al Moulla, K; O'Sullivan, N K; Fitzpatrick, J; Collier Cameron, A; Lakeland, B S; Cretignier, M; Mortier, A; Naylor, Tim; Llama, Joe; Aigrain, S; Hartogh, C; et al. (Monthly Notices of the Royal Astronomical Society, 2025)