Cosmic Scale
NGC 4889
Ultramassive black hole · 308 million light-years
How big is NGC 4889?
NGC 4889 is about 0.01 light-years across.
See NGC 4889 in 3D, at true scale
NGC 4889 is a giant elliptical galaxy in the Coma Cluster, hosting one of the largest black holes ever weighed: about 21 billion Suns. It is a dormant quasar — it once blazed, and now it is quiet.
At a glance
| Diameter | 0.01 light-years |
|---|---|
| Mass | 4.18 × 10⁴⁰ kg |
| Diameter compared with Earth | 9.7 × 10⁶ × Earth |
| Distance | 308 million light-years |
| Black hole | 21 billion Suns |
| Type | Supergiant elliptical |
| Cluster | Coma Cluster |
Good to know
- When it was active, its quasar would have outshone the whole galaxy.
- Its black hole's event horizon is about 12 times wider than Neptune's orbit.
- Stars near the centre move so fast that the black hole's mass can be read directly from their speeds.
- Next smaller: M87* · 3.8 × 10¹⁰ km
- Next larger: Holmberg 15A* · 0.03 light-years