On the basis of new experimental data, Brünken et al.
reported the tentative detection of cyanic acid, HOCN, in existing data observed toward the
Galactic center source
Sgr B2 in 2009. The four lines that match the experimental
data were reported in two published papers from the 1980s by
Cummins et al. and
Turner and an unpublished survey by
Remijan et al. from 2008. In the following year,
Brünken et al. published a follow-up study
that confirmed that the four lines are present in other sight lines in the extended Sgr B2 region.
HOCN is less stable than
isocyanic acid (HNCO), which has been a known astromolecule
for over four decades. A third isomer,
fulminic acid (HCNO), has also been observed, while the
fourth, isofulminic acid (HONC) has only be observed in the
lab and not yet in space.
shown that both HNCO and HOCN can give rise to the
cyanate anion if they transfer a proton to
ammonia in interstellar ice.