Seasonal evolution of CN, CH, and CH abundances in Titan’s lower stratosphere M. Sylvestre, N. A. Teanby, S. Vinatier, S. Lebonnois and P. G. J. Irwin A&A, 609 (2018) A64 Published online: 08 January 2018 DOI: 10.1051/0004-6361/201630255