a huge number of observatories (see note 5) are mentioned. i am not sure they’re all professional, even. does anyone have the background story? is this some kind of crowd-sourced approach that uses (well-equipped) amateurs? if so, it’s amazingly cool that they’ve ended up co-authors on a nature paper!
[edit: i asked the wife, who’s a chilean astronomer, but she doesn’t know (the chileans listed are all at other universities).]