Opening the 100-Year Window for Time Domain Astronomy
  The large-scale surveys such as PTF, CRTS and Pan-STARRS-1 that have emerged
within the past 5 years or so employ digital databases and modern analysis
tools to accentuate research into Time Domain Astronomy (TDA). Preparations are
underway for LSST which, in another 6 years, will usher in the second decade of
modern TDA. By that time the Digital Access to a Sky Century @ Harvard (DASCH)
project will have made available to the community the full sky Historical TDA
database and digitized images for a century (1890--1990) of coverage. We
describe the current DASCH development and some initial results, and outline
plans for the "production scanning" phase and data distribution which is to
begin in 2012. That will open a 100-year window into temporal astrophysics,
revealing rare transients and (especially) astrophysical phenomena that vary on
time-scales of a decade. It will also provide context and archival comparisons
for the deeper modern surveys
