2018 Aug 20–22 in Vienna, Austria, during the IAU GA

There is a large number of historical observations of transient celestial phenomena, always noticed as (problematic?) deviation from the otherwise seemingly eternal, unchanging heavens. In a new area called Terra‒Astronomy, we study transient astrophysical phenomena which potentially affect Terra (e.g. climate, biosphere, etc.) such as solar activity and nearby supernovae ‒ and we investigate them with terrestrial archives, both natural archives (e.g. 14C in trees and 10Be in polar ice as solar activity proxies, or 60Fe in the ocean crust indicating a nearby supernova) and historical archives (e.g. observations recorded in previous centuries to millennia). Written records from all civilizations offer high temporal and spatial resolution, e.g. for aurora observations to reconstruct solar activity. It is essential to correctly understand the historical reports, which are written texts in old to ancient languages, using a different terminology. True understanding means considering intentions of the authors, possible narratives and hidden quotations, etc.


– Understanding historical records from different cultures
– Criteria to classify naked-eye observations (e.g. aurorae, comets, sunspots, halo displays)
– Reconstruction of solar activity for the past millennia with telescopic and naked-eye sunspots as well as aurorae (possibly also with solar-wind-blown comet tails)
– Small solar system bodies (comets, meteors, and their connection)
– Earth rotation and moon orbit acceleration from historical eclipses and other occultations
– Historical novae and supernovae (possibly also SN impostors, kilo-novae, etc.)
– Exchange input from and to astronomy with other disciplines such as history, chronology,               geophysics, etc.