ZRUŠENO Přednáška Applied Historical Astronomy

Title: Applied historical astronomy: rapid color change in Betelgeuse, historical supernovae, and solar activity reconstruction

Abstract: Historical (pre-telescopic) celestial observations are applied in various fields of astrophysics as epistemic key, namely to study long-term secular effects by observations. We present four examples from our recent studies: Historical supernova observations can constrain sky location, age, and supernova type as well as light curve and color evolution (in particular the age of remnants like neutron stars and gas shells much better than astrophysical methods); comet orbits to study, e.g., so-called non-gravitational effects and outgassing; and solar activity reconstruction with historical naked-eye sunspots and aurorae (plus radiocarbon). Finally, we will also summarize our recent finding, that Betelgeuse changed color in the last two millennia from yellow (B-V=1.0 mag) to red (B-V=1.8 mag) from both several quantifiable historical reports and theoretical model tracks (e.g. the MESA/MIST 14 solar mass track); this is the first time that we can follow a bright supergiant by crossing the Hertzsprung gap.