Shadow on the sky

I congratulate my Event Horizon Telescope colleagues on an amazing achievement. What an amazing image of the shadow of the black hole in M87.

Against a black background, a red-orange ring with an unmistakeable dark center. The ring is asymmetrically brighter on the bottom half than the top.
The shadow of the black hole in M87.

The only way that the shadow in M87 could have been resolved by EHT is if we were right in our mass determination in Gebhardt et al. (2011). Our stellar dynamical mass estimate (scaled to their distance) was (6.2 ┬▒ 0.4) ├Ś 109┬áM┬ásun, and their mass estimate is (6.5 ┬▒ 0.7) ├Ś 109┬áM┬ásun. So there is very good agreement on this and, among other things, the EHT result is a great corroboration of the stellar dynamical mass estimation technique.