Isotopic abundance of nitrogen and carbon in distant comets J. Manfroid, E. Jehin, D. Hutsemékers, A. Cochran, J.-M. Zucconi, C. Arpigny, R. Schulz and J. A. Stüwe A&A, 432 1 (2005) L5-L8 Published online: 22 February 2005 DOI: 10.1051/0004-6361:200500009