Sagittarius A*
The black hole at the centre of the Milky Way, about four million times the Sun's mass.
Sagittarius A* (pronounced "A-star") is the supermassive black hole at the centre of our galaxy. It holds about four million times the mass of the Sun in a region smaller than Mercury's orbit.
Astronomers proved it was there by tracking stars that whip around it, work that won the 2020 Nobel Prize in Physics. In 2022 the Event Horizon Telescope released the first image of it: a glowing ring of hot gas around a dark shadow.
Key facts
- Distance
- About 26,000 light-years
- Mass
- About 4 million Suns
- First image
- 2022, Event Horizon Telescope
- Nobel Prize
- 2020, for proving it exists
Sagittarius A* in Comet Courier
Sagittarius A* is the destination. It sits dead ahead for the whole sector, growing until it fills the sky, and its gravity makes your engine strain and burn fuel faster. At the end you ride its photon ring, the thin circle where light orbits the hole: time slows, echoes of the places you passed circle around you, and the message is delivered.