The detection of hydrogen fluoride (HF) was reported in 1997 by
Neufeld et al.
It was observed toward Sgr B2 with the Infrared Space Observatory.
Confirming observations include two detections with Herschel,
toward Orion KL by Philips et al. in 2010 and
toward IRC +10216 by Agúndez et al. in 2011.
HF was detected toward galaxy Markarian 231
by van der Werf et al. in 2010.
Hydrogen fluoride and its solvated form,
hydrofluoric acid, are well-known and much used
in terrestrial chemistry. Although it is a
weak acid at
low concentrations, it behaves like a strong acid when it is very concentrated.