The DASCH Project - Ten Years Later

Saturday, November 7 @ 7:00 PM via Zoom

Contact Steve Hubbard (cstahhs@gmail.com) for Zoom Meeting link and information. 

Our speaker at the November meeting will be Dr. Jonathan (Josh) Grindlay from the Harvard/Smithsonian Center for Astrophysics. Josh will discuss the history and scientific results of the DASCH project (Digital Access to a Sky Century at Harvard). This is the tenth anniversary of Josh’s talk to Skyscrapers in November 2010. Ten years ago Josh came to share this exciting new project he was leading, the digitization of the entire Harvard plate stack collection.

Harvard College Observatory houses a collection of over 500,000 astronomical glass plates, most of which are 8” x 10”. There are also several thousand 11 x 17 plates as well as 4 x 5 plates. They cover both the Northern and Southern skies and span over 100 years. This is the largest collection in the world and also spans the longest time scale. Researchers wanting access to the data have always had to travel to Cambridge and manually find plates in the stacks, look at them on a light table and retrieve the data they needed for their research. The purpose of the DASCH project is to digitally scan the plates, measure the location and magnitude of all stars on the plate and then to store the results in a database for access from anywhere.

The photography on plates began in 1877 when E. C. Pickering became the director of Harvard College Observatory. In 1886 Anna Draper bequeathed a grant in the name of her deceased husband, Henry Draper, who had been interested in both photography and spectroscopy. In 1889 photography also began in Peru and later also from S. Africa, thus covering the entire sky. Study of the collection by a dedicated group of women “computers“ led to fundamental understanding of the nature and distance to stars and “nebulae“. Some of you may remember the talk to Skyscrapers by Dava Sobel on her history of the computers called “The Glass Universe “. 

At the conclusion of his talk in 2010 Josh invited any interested Skyscrapers to volunteer to help with the plate scanning. Ray Kenison and Steve Siok took up this offer and for nine years went to CfA and scanned each Thursday. This was only stopped because of the current pandemic. As an interesting side note, E. C. Pickering met an early death in 1918 because of the flu pandemic.

Please make an attempt to view this ZOOM meeting with your fellow Skyscrapers and enjoy the stories and results with Josh. Hope to see you then!

Dr. Jonathan Grindlay received his B.A  degree in Physics from Dartmouth College in 1966 and his Ph.D. in Astronomy from Harvard in 1971. His primary areas of research interest are high energy astrophysics and compact objects. He has led the DASCH project since its inception and it has allowed him to lead research in “Time Domain Astronomy”. Josh currently holds the Robert Treat Paine chair in Practical Astronomy. He shares this honor with his predecessors E. C. Pickering, Harlow Shapley, Donald Menzel and Irwin Shapiro. Additionally Josh has just been awarded a Legacy Fellow honor from the American Astronomical Society.