Plate Archive Search Tool (PAST)


Thanks to a generous grant from the  Ahmanson Foundation and from the The Kenneth T. and Eileen L. Norris Foundation, archivists have cataloged a portion of the Observatories' unique collection of some 200,000 astronomical photographic plates. 

This effort is focused mainly on direct images of galaxies, nebulae, stars, and star clusters, and on stellar spectra.  Much of Carnegie's large holding of solar plates is being cataloged and digitized through a separate NSF-funded project at UCLA.

So far, 95% of the non-solar direct image plates have been cataloged.  Work will continue on the remaining 5% of the direct images and the spectroscopic plates as funding permits.  The catalogs of images of solar-system objects and the Moon are currently being transferred to the online database.

Search Options

Plate Retrieval Policy

The plate collection is intended for scientific research purposes by accredited professional astronomers only.  Initial inquiries about a particular plate or plates should be directed to Kit Whitten. Please keep in mind that there is no staff directly dedicated to the collection.  We will try to locate plates in a timely manner, but do not have the capacity for broad searches or assisting in research.  In some circumstances it may be possible to arrange for site visits by astronomers who wish to come to Pasadena and access the collection with the oversight of Observatories' staff.


Thanks go to George Carlson and Donna Kirkpatrick, who did the bulk of the work by entering the data from the envelopes of the glass plates.  Chris Burns is responsible for the online interface to the database.