We report the discovery in the ISO/SWS spectrum of the post-AGE star HR 404
9 of emission bands due to O-17 and O-18 isotopes locked up in CO2 molecule
s. It is the first time these isotopomers are detected outside the solar sy
stem. Isotopic ratios derived in the optically thin limit are as low as O-1
6/O-17 = 8.3 +/- 2.3 and O-16/O-18 = 6.9 +/- 0.9. These values are at least
one order of magnitude lower than ally previously determined isotopic rati
o in any type of evolved star.