The Digital Access to a Sky Century @ Harvard (DASCH) is a project at the Harvard College Observatory that aims to digitize the majority of the Astronomical Photographic Plate Collection's 500,000 glass plate negatives and produce full photometry results for the entire sky. The stars photographed on glass plates between 1880s-1990s allow astronomers to study how the sky has changed over one hundred years. The scope of DASCH is unique in that it covers the entire sky for a very long period of time.

Peranso makes use of data from the DASCH project, which is grateful for partial support from NSF grants AST-0407380, AST-0909073, and AST-1313370.