PHOTODISSOCIATED H-I IN NGC-2023

We report the detection of photodissociated H I tovvard the reflection nebula NGC 2023. The Very Large Array observations reveal compact (si milar to 0.3 pc) emission associated with the source. The observed spe ctrum has a double-peaked profile that we believe is caused by absorbi ng foreground neutral gas. We corrected the observed spectrum for the absorption, and determined with this absorption-corrected profile an H I column density and mass of 1.7 x 10(21) cm(-2) and 1.2 M., respectiv ely. This column density agrees well with theoretical model prediction s. The HI 21 cm map shows a morphology very similar to that present in the images of [C II] at 158 mu m, HIRES 60 mu m IRAS, and POSS optica l.