HIFI detection of hydrogen fluoride in the carbon star envelope IRC +10216 M. Agúndez, J. Cernicharo, L. B. F. M. Waters, L. Decin, P. Encrenaz, D. Neufeld, D. Teyssier and F. Daniel A&A, 533 (2011) L6 Published online: 24 August 2011 DOI: 10.1051/0004-6361/201117578