Dimethyl ether in Orion

Seven new dimethyl ether transitions have been observed in emission from the direction of the Orion Nebula. Dimethyl ether has also been detected in Sgr B2 in weak emission from two rotational transitions. The observed high-resolution spectra from several of the Orion transitions exhibit well-resolved splittings due to internal motions in the molecule. All of the Orion signals are quite narrow (approx. =2.3 km s/sup -1/) and centered near =6.6 km s/sup -1/. Laboratory measurements of the rest frequencies of these same transitions are presented, along with the calculated relative intensities of the internal rotor split components.