We investigate how the gravitational field generated by line sources can be
characterized in Brans-Dicke theory of gravity. Adapting an approach previously
developed by Israel who solved the same problem in general relativity we show
that in Brans-Dicke theory's case it is possible to work out the field
equations which relate the energy-momentum tensor of the source to the scalar
field, the coupling constant ω and the extrinsic curvature of a tube of
constant geodesic radius centered on the line in the limit when the radius
shrinks to zero. In this new scenario two examples are considered and an
account of the Gundlach and Ortiz solution is included. Finally, a brief
discussion of how to treat thin shells in Brans-Dicke theory is given.Comment: 21 pages, RevTex; added a discussion on the Gundlach and Ortiz
solutio