Latest measurements of the stars orbiting the Milky Way’s Core Black Hole – euphoniously called “Chandra” by Stephen Baxter in his ‘Xeelee’ saga – have determined its mass and distance to new levels of accuracy:
[2101.12098] Improved GRAVITY astrometric accuracy from modeling of optical aberrations
R_o = 8,275 parsecs +\- 9.3 parsecs and a Chandra mass of (in 106 M_sol) 4.297 +\- 0.013.
In light-years that’s almost 27,000 and in round terms, 4.3 million Suns mass, an Event Horizon 12.7 million kilometres in radius.