DIFFUSE INTERSTELLAR BANDS TOWARDS BD-DEGREES 1964 - A NEW REFERENCE TARGET(63)

We report the discovery of a remarkable target concerning the Diffuse Interstellar Bands (DIBs), namely BD+63 degrees 1964. The unusual high DIB strengths in this object allow to confirm DIBs that were so far d enoted only as ''probable'', because of their intrinsic weakness in mo st lines-of-sight. Due to specific line-of-sight conditions, the high reddening and the early spectral type of the star, this object is prop osed as a new reference star for DIB measurements. We compared the spe ctrum of BD+63 degrees 1964 to the spectrum of the well studied star H D183143. Line-of-sight parameters such a far UV extinction and Ca I ab undance indicate a denser environment towards BD+63 degrees 1964, whic h can shield molecules efficiently from far UV radiation above 6 eV. T he relative enhancement of narrow DIBs in BD+63 degrees 1964 versus HD 183143 is then discussed in the context of neutral fullerene compounds or large PAHs. The relative weakening of broad DIBs indicate carriers with higher photo-ionization potential and different recombination pr operties.