M87* size and scale context

M87* is the supermassive black hole at the center of Messier 87. The Event Horizon Telescope’s 2019 image of its glowing ring became the first direct image of a black hole’s immediate surroundings, turning a previously inferred boundary into a measurable true-scale object. Read its scale context, comparisons, and journey links on the canonical object page.

BetelgeuseRed supergiant star·1.05 billion km

VY Canis MajorisRed hypergiant star·1.98 billion km

Stephenson 2-18Extreme red supergiant candidate·~2.99 billion km

Solar SystemPlanetary system·9 billion km

M87*Supermassive black hole·38 billion km

Holm 15A*Ultramassive black hole·236 billion km

Scroll up for smaller

Scroll down for larger

Planetary systems

Solar System

The Solar System’s main planetary span extends from the Sun out to Neptune’s orbit, not to its far larger comet reservoirs. Beyond the planets it continues through the Kuiper Belt and, much farther out, the Oort Cloud, so the familiar planetary layout is only the compact inner start of the Sun’s domain.

Scale fact9 billion kmorbital diameter

Object class: Planetary system
Host: Sun
Estimated age: ~4.6 billion years

Black holes

M87*

Scale fact38 billion kmevent horizon diameter

Object class: Supermassive black hole
Host: Messier 87
Mass: ~6.5 billion solar masses

Black holes

Holm 15A*

Holm 15A* is the ultramassive black hole in the central galaxy of the Abell 85 galaxy cluster, measured at about 40 billion solar masses. That makes its event horizon enormous, while Holm 15A’s unusually diffuse center preserves evidence of the mergers that helped build it.

Scale fact236 billion kmevent horizon diameter

Object class: Ultramassive black hole
Host: Holm 15A, Abell 85
Mass: ~40 billion solar masses