SIMULTANEOUS INFRARED AND H-ALPHA MEASUREMENTS OF BE-STARS

The observed infrared excess in Be stars is usually interpreted as fre e-free and free-bound emission from a hot gas envelope around the Be s tar. This hot gas should also emit H-alpha line radiation. Earlier obs ervations had suggested that the infrared excess and Halpha radiation were not consistent with models in which they arise from the same ioni zed region; however the observations were made at different times. We have made simultaneous observation of infrared and H-alpha line radiat ion. Our observations imply that either both these radiations cannot a rise from the same hot gas or additional processes have to be invoked to account for the observed excess infrared radiation.