A size of ~1 AU for the radio source Sgr A* at the centre of the Milky Way

Zhi-Qiang Shen, K. Y. Lo, M. -C. Liang +2

Although it is widely accepted that most galaxies have supermassive black holes (SMBHs) at their centers^{1-3}, concrete proof has proved elusive. Sagittarius A* (Sgr A*)^4, an ext…