The detection of the unusual molecule carbodiimide (HNCNH) was reported in 2012 by
McGuire and co-workers toward the north
core of Sgr B2. The Sgr B2 (N), (M), and
(S) cores are all active
star forming regions. The
observations were made with the Green Bank Telescope.
The detection of HNCNH was unusual because it was observed in transmission rather than absorption (like most
astromolecules): the transitions were pumped by absorbing microwave energy and emitting it with enhanced
intensity, a process known as masering.
There has evidently not yet been confirmation of the detection of HNCNH by subsequent published observations.