Detection of circumstellar nitric oxide - Enhanced nitrogen abundance in IRC +10420 G. Quintana-Lacaci, M. Agúndez, J. Cernicharo, V. Bujarrabal, C. Sánchez Contreras, A. Castro-Carrizo and J. Alcolea A&A, 560 (2013) L2 Published online: 05 December 2013 DOI: 10.1051/0004-6361/201322728