4800 20200213105815.0 SCART-2020-0067 Pevtsov, Alexei Historical astronomical data: urgent need for preservation, digitization enabling scientific exploration 2019 Astro2020: Decadal Survey on Astronomy and Astrophysics, science white papers, no. 190 This white paper emphasizes critical importance of preservation, digitization and scientific exploration of historical astronomical data. It outlines the rationale, provides examples of new science with such data, and reviews the potential losses to science if nothing it done. NO Astronomical data History of astronomy Data digitization Griffin, Elizabeth Grindlay, Jonathan Kafka, Stella Bartlett, Jennifer Usoskin, Ilya Mursula, Kalevi Gibson, Sarah Pillet, Valentín Burkepile, Joan Webb, David Clette, Frédéric Hesser, James Stetson, Peter Muñoz-Jaramillo, Andres Hill, Frank Bogart, Rick Osborn, Wayne Longcope, Dana Bulletin of the American Astronomical Society 51 2019 3 190 frederic.clette@observatoire.be published in NONREF