2002A&A...382..291M

Deep optical CCD imaging and spectroscopic observations of four new nebular structures have been performed for the first time. Filamentary and diffuse emission is detected in this field located to the north-east of the CTB 80 supernova remnant (SNR). Two long filaments are discovered to the north of LBN 156, while a 23' long filament, emitting strongly in the [OIII] line, is present to the east of LBN 156. A complex and compact network of filaments is located close to the center of our field. Finally, the last new source of line emission detected in this field is mainly diffuse and patchy and its morphology displays a semi-circular shape. The long-slit spectra of these structures indicate emission from shock-heated gas and the observed variations in the [OIII] fluxes most likely reflect differences in the shock velocities. Weak radio emission at 4850 MHz seems correlated with almost all of the new structures. It is proposed that all these structures, with the possible exception of the brightest one, are part of a single supernova remnant. Detailed radio observations should allow the determination of the nature of the radio emission and provide a crucial test of our suggested intepretation.