Five years of optical and infrared monitoring of Betelgeuse with the Himawari-8 meteorological satellite

Red supergiants are a class of massive stars, who will soon end their lives as supernovae. Time variability at this stage, such as pulsation and mass loss, gives close insights into several fields including massive star evolution and supernova light curves. As a laboratory of the time variability of red supergiants, we focus on the Great Dimming of Betelgeuse in early 2020, an unusual fall and rise in the optical brightness by ~1.2mag. Here we present 16-bands photometry of Betelgeuse in 0.45-13.5micron from January 2017 to today making use of the images taken by the Himawari-8 meteorological satellite. Analyzing these light curves, we show that two mechanisms, a decreased effective temperature and an enhanced dust extinction, may have both contributed to the Great Dimming by the same amounts. We also discuss the future ability of meteorological satellites for the time-domain investigation of other evolved stars.