VAU or Vau can mean:

Nymphalis Vau-Album (Schiffermuller & Denis), a Holarctic Species (Lepidoptera Nymphalidae)
VizieR Online Data Catalog: Third Reference Catalogue of bright galaxies (RC3)
Prochlorococcus, a marine photosynthetic prokaryote of global significance
Oceanic 18S rDNA sequences from picoplankton reveal unsuspected eukaryotic diversity.
Third Reference Catalogue of Bright Galaxies. Volume I: Explanations and references. Volume II: Data for galaxies between 0h and 12h...
Revised Report on the Algorithmic Language Algol 60
Vaulot D: Prochlorococcus, a marine photosynthetic prokaryote of global significance
Enumeration and Cell Cycle Analysis of Natural Populations of Marine Picoplankton by Flow Cytometry Using the Nucleic Acid Stain SYB...
Third Reference Catalogue of Bright Galaxies
Report on the algorithmic language ALGOL 60