DASCH was the project to digitize the Harvard College Observatory’s Astronomical Photographic Glass Plate Collection for scientific applications. This enormous — multi-decade — undertaking was completed in 2024. Its legacy is DASCH Data Release 7, an extraordinary dataset that enables scientific study of the entire night sky on 100-year timescales.

This website provides technical information for scientific users of the DASCH data. You might wish to:

• Learn about Data Release 7
• Search Plates on Starglass

If you use the DASCH data for science, you are strongly encouraged to sign up for the DASCH Astrophysics email list, the preferred venue for announcements and discussions relating to all things DASCH:

For anything to do with the Harvard plates besides using the DASCH data for astrophysical research, visit the Plate Stacks website.

About the Plates

The Harvard College Observatory's Astronomical Photographic Glass Plate Collection (Plate Stacks) is the largest collection of its kind in the world. The core of the collection is over 550,000 glass plate negatives and spectral images, covering both the northern and southern hemispheres. The Harvard Plate Stacks make up over a century of irreplaceable scientific observations and represent the first full image of the visible Universe. Hundreds of women studied and curated the Harvard Plate Stacks while making discoveries of their own, but more often than not their work went unrecognized. The Center for Astrophysics is dedicated to understanding and undoing the erasure of these women’s contributions while advancing and enabling the creation of new knowledge using the Harvard Plate Stacks Collection. Visit the Plate Stacks website to learn more about this unique resource.

About the Project

The DASCH project was an enormous effort spanning two decades. Learn more about it on the About DASCH page, and meet the people behind DASCH. See the Acknowledgments page for information about the supporters that made DASCH possible.