Optical CCD imaging and spectroscopic observations of three supernova remnants have been performed for the first time .
Filamentary and diffuse emission is discovered from the supernova remnant G 67.7+1.8 located \sim 82 ^ { \prime } to the south of CTB 80 ’ s pulsar .
The H \alpha and sulfur emission are almost equally strong at a level of \sim 20 \times 10 ^ { -17 } erg s ^ { -1 } cm ^ { -2 } arcsec ^ { -2 } suggesting shock heated emission .
Electron densities less than 240 cm ^ { -3 } are estimated , while the weak [ O iii ] emission suggests shock velocities in the range of 60–80 km s ^ { -1 } .
Emission can also be seen in the ROSAT All Sky Survey data which indicate an extended hard X-ray source .
Emission from G 31.5–0.6 is detected only in the H \alpha + [ N ii ] image at a typical flux level of 35 \times 10 ^ { -17 } erg s ^ { -1 } cm ^ { -2 } arcsec ^ { -2 } .
The morphology of the observed radiation is diffuse and partially correlated with the non–thermal radio emission .
Deep long slit spectra detect sulfur line emission which is not strong enough to identify it as emission from shocked gas .
Finally , optical emission from G 49.2–0.7 is obscured by several dark nebulae which probably give rise to significant X-ray attenuation .
The H \alpha + [ N ii ] flux is typically \sim 40 \times 10 ^ { -17 } erg s ^ { -1 } cm ^ { -2 } arcsec ^ { -2 } while the [ S ii ] flux is very weak , not allowing its identification as shock heated .
However , a small area of \sim 3 ^ { \prime } \times 1 ^ { \prime } emits strong sulfur flux relative to H \alpha ( [ S ii ] /H \alpha \sim 0.6 ) .
This area is located in the south–east of G 49.2–0.7 , close to the outer boundaries of the X–ray and radio emission .
However , deep optical spectra would be required to firmly establish the nature of this emission and its association to G 49.2–0.7 .