An identification for "GEMINGA" (2CG 195+04) 1E 0630+178 : a unique object in the error box of the high-energy gamma-ray source.

In the search for counterparts for COS B high-energy gamma-ray sources, 2CG 195+04 was observed with the Einstein Observatory. Four sources have been found, three near to the detection limit and one, 1E 0630+178, at a flux level of approximately 2×10^-12 ergs cm^-2 s^-1. The 3arcsec HRI position has permitted an optical identification with a faint blue object, while VLA data at 6 cm do not show radio flux at the HRI position. The ratio L_x/L_v ≈ 1000, the lack of a radio counterpart, and the absence of temporal variability and of spatial extent in the X-ray data are unique. The very small interstellar absorption suggests a distance of approximately 100 pc (or less). Only a neutron star seems to come close to meeting the data; however, its characteristics would be different from those known so far.