GREAT confirms transient nature of the circum-nuclear disk M. A. Requena-Torres, R. Güsten, A. Weiß, A. I. Harris, J. Martín-Pintado, J. Stutzki, B. Klein, S. Heyminck and C. Risacher A&A, 542 (2012) L21 Published online: 10 May 2012 DOI: 10.1051/0004-6361/201219068