G 76.9+1.0, a supernova remnant with unusual properties.

G 76.9 + 1.0 is a non-thermal source near the galactic plane. VLA observations of the object at 1.49,4.86 and 8.44 GHz are presented. The integrated flux density at 1.49 GHz is 1.8 Jy. An extended envelope of size 9' x 12' surrounds a central structure of two lobes, separated by ~3', joined by a bridge of emission. The spectral index is α = 0.62+/-0.04 (where S is proportional to ν^-α^). The apparent elliptical shape at low levels may be partly produced by emission from a background ridge. The emission from G 76.9 + 1.0 is polarized, and the rotation measure (RM) is - 283 +/- 75 rad m^-2^. Comparison of this value with the RM of extragalactic sources suggests that G 76.9 + 1.0 is more distant than 7 kpc and could be extragalactic. G 76.9 + 1.0 cannot be a normal galaxy, primarily because it is deficient in infrared emission. The two-lobed structure is suggestive of a radio galaxy, but the steep outer edge, characteristic of radio galaxies, is absent in this object. G 76.9 + 1.0 strongly resembles two objects which are acknowledged SNRs, G 18.9-1.1 and DA 495. It is interpreted as a filled-centre SNR, whose steep spectral index may possibly be explained by the effects of age. At a distance of 7 kpc, its size is approximately 18 x 24 pc.