Production of deuterons and antideuterons was studied by the NA49
experiment in the 23.5% most central Pb + Pb collisions at the top CERN
Super Proton Synchroton (SPS) energy of root s(NN) = 17.3 GeV. Invariant
yields for (d) over bar and d were measured as a function of centrality
in the center-of-mass rapidity range -1.2 < y < -0.6. Results for (d)
over bar (d) together with previously published (p) over bar (p)
measurements are discussed in the context of the coalescence model. The
coalescence parameters B-2 were deduced as a function of transverse
momentum p(t) and collision centrality