Preliminary results on the circumstellar envelopes of alpha Ori and R Leo from CO 4.6 mu m line emission

CO 4.6 mu m vibration-rotational lines are detected in fluorescent emission from the inner regions of the Betelgeuse (a Orionis) and R Leonis stellar winds. The spatially and spectrally resolved 1-0 R(1), R(2), and R(3) line profiles are found to be highly useful probes of circumstellar shells. The current data sample only a few regions of the circumstellar shells of the p rogram stars. However, now it should be possible to obtain envelope maps an d absolute flux estimates, allowing new independent estimates of mass loss rates. This will open up new possibilities in the study of the structure an d dynamics of stellar winds around red giants. The temperature 4 " away fro m a Ori is found to be 38(-5)(+6) K. For R Leo the temperature 4 " North is derived to be 24(-2)(+3) K and 4 " South 35(-4)(+7) K.