The 59 s periodicity of 2CG 195 + 4 (Geminga) and a low-mass binary model

An examination of the existing period searches for 2CG195 + 4 leads to the conclusion that the 59 second periodicity is highly significant only for the 1981 March 17–18 detection of Bignami, Caraveo & Paul (1984). The statistical significance is increased substantially if the pulsation period is half the previously reported value. The period derivative is not well determined. Here we propose that 2CG 195 + 4 is a neutron star powered by accretion from a low (≲ 1M _⊙) mass main-sequence companion. A distance of a few hundred pc would imply that the neutron star is a fast rotator and is spinning down.