Sagittarius A*: Our Galaxy's Center

Environmental & Science Education, STEM, Cosmology, Astrophysics, Astronomy, History of Science, Nature of Science

Ed Hessler 

The citation for work on the massive black hole at the center of our galaxy for which the Nobel Prize committee awarded the 2020 physics award to Reinhard Genzel and Andrea Ghez used an interesting phrase - it was called "a supermassive compact object" not a black hole. It is an example of the conservative nature of science, given the evidence. By now it is well known hat the object is a monstrous black hole at the center of our galaxy. 

It's appearance- only the second direct  image of a black hole, finally yielded to scientific, engineering, and computing technology and ingenuity. the data collection involved a global network of telescopes.A report on the first direct image of a black hole is reported here.

I'd been waiting for the BBC to report for the usual reasons -- clear explanations, images, illustrations, and maps. Jonathan Amos  reports who notes that the "picture is a technical tour de force. It has to be.

"At a distance of 26,000 light-years from Earth, Sagittarius A*, or Sgr A* for short, is a tiny pinprick on the sky. To discern such a target requires incredible resolution." The pinprick is not small - 40 million miles (~60 million km) across. Nor is it a lightweight - some four million times the mass of the solar system's sun.