Key facts
- Category
- Black holes
- Object class
- Supermassive black hole
- Host
- Milky Way
- Scale fact
- 24.5 million kmevent horizon diameter
- Mass
- ~4.3 million solar masses
Sagittarius A*
24.5 million kmevent horizon diameter
Visual creditscaleofspace.org / CC BY-NC 4.0
Details
Sagittarius A* is the supermassive black hole at the center of the Milky Way. Event Horizon Telescope observations imaged the glowing material around it, resolving a radio ring about 64 million kilometers across around a black hole of roughly 4.3 million solar masses.
Decades of tracking stars around the center of the Milky Way place about 4.3 million solar masses inside a region small enough to identify Sagittarius A* as a supermassive black hole. Those stellar orbits provide the mass measurement; the black hole is not weighed from its apparent image size.
The Event Horizon Telescope resolved a bright radio ring about 52 microarcseconds wide, or roughly 64 million kilometers across at the Galactic Center. That ring is emission from hot plasma distorted by gravity and is larger than the roughly 24.5-million-kilometer event-horizon diameter represented on this scale.
Links
- Editorial guides
- Universe journey
- Milky Way
- Preset views
- Wikipedia
- Sagittarius A* on Wikipedia
Size neighbors
Objects near Sagittarius A* on the scale
Shared physical scale
29.1billion km
Sources
References for Sagittarius A*
Measurements and descriptive context are compiled by the Scale of Space team from the references below. If you find an error, please let us know.
- Sagittarius A* — Wikipedia
- Visual: scaleofspace.org / CC BY-NC 4.0
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About
Scale of Space is a scroll-based journey through the universe, placing objects on a single logarithmic scale so you can compare size across an unbroken range.
Guides explain selected parts of that range, while focused views filter the objects by subject.