DASCH (Digital Access to a Sky Century @ Harvard)

The Harvard Astronomical Glass Plate Collection is an archive of roughly 500,000 images of the sky preserved on glass photographic plates, the way professional astronomers often captured images in the era before the dominance of digital technology. These plates are more than historical curiosities: they provide over a century’s worth of data that can be used by contemporary astronomers to trace how objects in the night sky change over periods from years to decades.

For that reason, the DASCH (Digital Access to a Sky Century @ Harvard) team are working to digitize the plates for digital storage and analysis. The process can also lead to new discoveries in old images, particularly of events that change over time, such as variable stars, novas, or black hole flares.

Black dots representing stars on a white field.

A galaxy as captured on one of the glass plates in the CfA's collection.

Project Status

The DASCH project has been a herculean effort spanning two decades. In order to ensure that the plate scanning is brought to completion, and that the resulting data are archived and as useful as possible, the project is undergoing a technical overhaul under the direction of the Wolbach Library. During this time, our servers will be down and access to DASCH data via existing interfaces will be limited. Please contact Purvang Patel, Harvard College Observatory Executive Director, if you have questions. We will do everything we can to respond to your request.

By making the DASCH project part of the Wolbach Library's portfolio of initiatives we are able to more fully benefit from resources available through the Harvard Library and the Weissman Preservation Center, in addition to gaining access to support from our expert colleagues at the Smithsonian Institution.

We are excited about this new phase of the project and looking forward to sharing updates as we make progress.

DASCH (Digital Access to a Sky Century @ Harvard)

Project Status

Experts

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