2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/176731We show how, in heterotic M-theory, an M5-brane in the 11-dimensional bulk may end on an ``M9-brane'' boundary, the M5-brane boundary being a Yang monopole 4-brane. This possibility suggests various novel 5-brane configurations of heterotic M-theory, in particular a static M5-brane suspended between the two M9-brane boundaries, for which we find the asymptotic heterotic supergravity solution.4 pages, 3 figures, version to appear in PRLHigh Energy Physics - Theorytext