Ultraviolet DIB at 1369 A Arising in Molecular Clouds

Abstract

Hubble Space Telescope (HST) and IUE observations of the weak unidentified interstellar line 1369 A in nine early type stars are discussed. This absorption feature might be a diffuse interstellar band (DIB). We have found good correlation between the equivalent widths of the 1369 A line and the interstellar CO A¹Pi-X¹Sigma (6--0) band at 1367.5 A and no correlation with the interstellar atomic lines of NiII, NaI, HI. This indicates that carrier of this unidentified feature is associated with molecular clouds.