Microwave detection of interstellar HDO.

Nitric oxide (/sup 14/N/sup 16/O) has been detected in the source Sgr B2 by means of its two /sup 2/Pi/sub 1/2/, J=3/2..-->..1/2, rotational transitions at 150.2 and 150.5 GHz. The inferred column density and related abundance are N/sub NO/approx.2 x 10/sup 16/ cm/sup -2/ and X (NO) approx.1 x 10/sup -8/, respectively.