O(6,22) BPS Configurations of the Heterotic String

We present a static multi-center magnetic solution of toroidally compactified heterotic string theory, which is T-duality covariant. The space-time geometry depends on the mass M and on the O(6,22)-norm N of the magnetic charges. For different range of parameters (M,N)-solution includes 1) two independent positive parameters extremal magnetic black holes with non-singular geometry in stringy frame ($a=1$ black holes included), 2) $a=\sqrt 3$ extremal black holes, 3) singular massive and massless magnetic white holes (repulsons). The electric multi-center solution is also given in an O(6,22)-symmetric form.