GRAVOMAGNETIC TENSING BY NUT SPACE

Using the fact that the null geodesics in NUT space lie on spatial con es, we consider the gravomagnetic lens effect on light rays passing an NUT deflector. We show that this effect changes the observed shape, s ize and orientation of a source. Compared with the Schwarzschild lens. there is an extra shear (a differential twist around the lens axis) d ue to the gravomagnetic field which shears the shape of the source. Gr avomagnetic monopoles can thus be recognized by the spirality that the y produce in the lensing pattern. All the results obtained in this cas e (magnification factor, orientation of images, multiplicity of images , etc.) depend on Q, the strength of the gravomagnetic monopole repres ented by the NUT metric. One recovers the results of the usual Schwarz schild lens effect by setting this factor equal to zero.