#  Our Collection 

 



The Harvard Plate Stacks collection stretches back to the dawn of photography to the present. At the core of our collection are the nearly 600,000 glass plate negatives of the night sky. This represents the largest collection of its type in the world, where nearly one out of four of these astronomical plates resides within our collection. This collection was founded through the support and endowment left by Anna Palmer Draper in honor of her late husband, Henry Draper. Central to our history is the individual and pioneering legacies of over 200 Women Astronomical Computers whose discoveries help shape the way we see the universe today.

The astronomical size of the collection means much of our holdings has yet to be inventoried or catalogued. However, our database [StarGlass](https://starglass.cfa.harvard.edu/) is over 1.2 petabytes of our collection, digitized and made accessible. This represents two of our major collections, 60% of our glass plates and their jackets, and over 2,500 scientific notebooks made by those who worked within our collection, known as [Project PHaEDRA](https://platestacks.cfa.harvard.edu/project-phaedra). This is the easiest way to gain access to specific materials and is even available for you to search in a customized way through [open API access](https://starglass.cfa.harvard.edu/docs/api/index.html).

While StarGlass provides a universe of discovery, there are key parts of our collection yet to be included in it. Almost all of our direct image plates are either fully digitized or have a metadata record in StarGlass, nearly 200,000 glass plates of individual spectra and spectral field plates are not included. Also, large holdings from the HCO and SAO Meteor departments have not yet been included in the database.

Finally, our collection includes the very earliest examples of astrophotography and analogue photographic materials. These include daguerreotypes, Apollo lunar photography, sunspot plates, and 150 years of eclipse photographs. Our collection also holds significant archival materials and ephemera.

Finally, our collection continues to grow. Over the decades, different departments at the Center for Astrophysics have deposited their analogue materials in our holdings. Relatively small but equally important photographic materials, including thousands of spectra and plates, have also been given to the Plate Stacks by outside organizations and individuals. The curators of the collection have also actively acquired materials related to our holdings and history. You can read more about the kinds of materials we have added to and are looking to add to our collection by reading our [collection development policy](https://platestacks.cfa.harvard.edu/collection-development).

[Contact us](mailto:HarvardPlateStacks@cfa.harvard.edu) to ask for help in finding materials or to inquire if we have items in our collection.



 

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### Browse 

 

[StarGlass](https://starglass.cfa.harvard.edu/)

[PHaEDRA Notebooks](https://library.cfa.harvard.edu/project-phaedra-finding-aid)

[The Williamina Fleming Collection Finding Aid](https://library.cfa.harvard.edu/plate-stacks/williamina-fleming-collection)

[DASCH](https://dasch.cfa.harvard.edu/)



 



      ![Glass plate B20678](/sites/g/files/omnuum2761/files/styles/hwp_1_1__480x480/public/2024-09/b20678_p-web.jpg?itok=AwaUwwXB) 

 

 

  Glass plate B20678   

 



 

 

 

##  Explore the Plate Stacks