Opening the 100-Year Window for Time Domain Astronomy

TL;DR

This paper discusses the DASCH project which digitizes a century of sky images, enabling long-term time domain astronomy research and complementing modern surveys with historical data.

Contribution

It introduces the DASCH project, detailing its development, initial results, and plans to provide a 100-year archival database for time domain astrophysics.

Findings

DASCH has digitized a century of sky images from 1890 to 1990.

The project reveals rare transients and long-term variable phenomena.

It provides historical context for modern astronomical surveys.

Abstract

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