Building a stellar time machine

July 7, 2009 by Alvin Powell

Jonathan Grindlay (from left), Paine Professor of Practical Astronomy, Alison Doane, curator of plate stacks, Edward Los, software engineer, and Sumin Tang, research assistant in astronomy, are part of the DASCH project, which aims to digitize 525,000 glass photographic plates taken in the last century.

Photograph here:

http://www.physorg.com/news166197904.html

(PhysOrg.com) -- Harvard researchers are building a celestial time machine that lets astronomers look back at hundreds of thousands of objects in Earth’s skies over the past century.

The effort aims to digitize 525,000 glass photographic plates taken at observing sites around the world between the 1880s and the 1980s. The collection, the largest such in the world, contains a treasure trove of largely unexamined data, according to Paine Professor of Practical Astronomy Jonathan Grindlay, who is leading the digitizing effort.

Grindlay said each of the plates has been examined for one or a few objects of interest to specific astronomers. When one considers that each plate holds images of upwards of 100,000 objects and that each visible object has been photographed between 50 and 3,000 times over the years, the potential knowledge about the changing universe hidden in the Harvard College Observatory plate stacks is enormous.

“DASCH will look at every object on the plate with specially developed software and measure its brightness. You can not know what you’re looking for and still find something,” Grindlay said. “We’re part of a wave that is looking at the sky for its variable objects, for everything that goes bump in the night — and that turns out to be a lot. DASCH will open a new window for time domain astronomy.”

Full article here:

http://www.physorg.com/news166197904.html

The Web site for DASCH is here:

http://hea-www.harvard.edu/DASCH/