DASCH is the project to digitize the Harvard College Observatory’s Astronomical Photographic Glass Plate Collection for scientific applications. This irreplaceable resource provides a means for systematic study of the sky on 100-year time scales.
This website provides technical information for scientific users of the DASCH data. You might wish to:
- Search Plates on StarGlass
- Search Plates on Cannon (Traditional)
- Search Lightcurves
- Learn about the data
If you use DASCH for science, you are strongly encouraged to sign up for the DASCH Astrophysics email list, the preferred venue for announcements and discussions relating to DASCH:
For anything to do with the Harvard plates besides using the DASCH data for astrophysical research, visit the Plate Stacks website.
2024 September 9: The spatial restrictions on DASCH data access through the traditional “Cannon” data access portal have been lifted. Using this portal you can now access lightcurves and postage stamps for all regions of the sky, not just ones with b > 0. Note that it has been possible to access data for the whole sky for some time through the daschlab Python analysis framework.
2024 March 28: After eighteen years, 470,000 scans, about half a petabyte of data, 15 billion photometric measurements, a flood, and a pandemic, the final plates in the DASCH sample were scanned today. DASCH scanning is now complete. Much work remains to be done, however! The full news item describes what’s next.
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 has been a herculean 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 have made DASCH possible.