V 439 Cyg: possible optical counterpart of the X-ray source 1H 2018+366 (=4U 2019+39?) and of the gamma-ray source 2CG 075+00

The authors suggest the B3e(?) star V439 Cyg as possible counterpart of the X-ray source 1H 2018+366 on the basis of positional coincidence and similarity with the optical counterparts of galactic binary systems. The peculiarity of the proposed object is enhanced by the fact that V439 Cyg is coincident with the infrared source IRAS 20198+3716 and lies in the compact H II region G 75.77+0.34 that shows a well defined thermal radio spectrum. Furthermore it is enclosed in the error box of the COSB source 2CG 075+00.