The extended supernova remnant G 116.5+1.1 was observed in the optical emission lines of H \alpha + [ N ii ] , [ S ii ] and [ O iii ] ; deep long–slit spectra were also obtained .
The morphology of the remnant ’ s observed emission is mainly diffuse and patchy in contrast to the known filamentary emission seen along the western limb .
The bulk of the detected emission in the region appears unrelated to the remnant but there is one area of emission in the south–east which is characterized by a [ S ii ] /H \alpha ratio of \sim 0.5 , implying a possible relation to G 116.5+1.1 .
If this is actually the case , it would imply a more extended remnant than previously realized .
Emission in the [ O iii ] 5007 Å line image is not detected , excluding moderate or fast velocity shocks running into ionized interstellar clouds .
Our current estimate of the distance to G 116.5+1.1 of \sim 3 kpc is in agreement with earlier estimates and implies a very extended remnant ( 69 pc \times 45 pc ) .

Observations further to the north–east of G 116.5+1.1 revealed a network of filamentary structures prominent in H \alpha + [ N ii ] and [ S ii ] but failed to detect [ O iii ] line emission .
Long-slit spectra in a number of positions provide strong evidence that this newly detected emission arises from shock heated gas .
Typical H \alpha fluxes lie in the range of 9 to 17 \cdot 10 ^ { -17 } erg s ^ { -1 } cm ^ { -2 } arcsec ^ { -2 } , while low electron densities are implied by the intensities of the sulfur lines .
Weak emission from the medium ionization line at 5007 Å is detected in only one spectrum .
Cool dust emission at 60 and 100 microns may be correlated with the optical emission in a limited number of positions .
Surpisingly , radio emission is not detected in published surveys suggesting that the new candidate remnant may belong to the class of “ radio quiet ” supernova remnants .