2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/35306We analyze a class of exact type II solutions of the Robinson-Trautman family which contain pure radiation and (possibly) a cosmological constant. It is shown that these spacetimes exist for any sufficiently smooth initial data, and that they approach the spherically symmetric Vaidya-(anti-)de Sitter metric. We also investigate extensions of the metric, and we demonstrate that their order of smoothness is in general only finite. Some applications of the results are outlined.12 pages, 3 figuresGeneral Relativity and Quantum Cosmologytext