A SEARCH FOR OBSERVATIONAL EVIDENCE OF OH MOLECULE PHOTOPRODUCTION

Observational evidence for OH molecule photoproduction by the interste llar UV radiation in the circumstellar envelopes of Mira variables has been searched for. A sample of Me-type Miras was observed in the main OH maser lines with the Nancay radio telescope. Two new lines were de tected. The intensity of the 156.5-nm wavelength interstellar radiatio n is estimated by integration of the observed UV light of OB stars in common star catalogues. A statistically significant trend is found tha t OH Miras are illuminated by stronger UV fields than non-OH objects.