Extended red emission and unidentified infrared bands in the galactic compact H II region Sh 152

We present visible and infrared images and low- dispersion visible spectra of the galactic compact H ii region Sh 152. The spatial distribution of the Extended Red Emission (ERE) over the nebula is found to coincide with that of the ion- ized hydrogen emission and to differ from that of the Unidenti- fied InfraRed Bands (UIRBs) emission at 3.3 and 6.2 m. This result and other considerations are in favour of grains as carriers of the ERE. It is shown that nanosized silicon particles could account for the ERE in terms of luminescence, an interpretation which, however, suffers from some limitations.