Cosmic Scale
Phoenix A*
Ultramassive black hole · 5.8 billion light-years
How big is Phoenix A*?
Phoenix A* is about 0.06 light-years across.
See Phoenix A* in 3D, at true scale
Phoenix A* is the black hole at the heart of the Phoenix Cluster, and current estimates put it near 100 billion Suns — possibly the most massive known. Those estimates are indirect and uncertain, so treat the number with care.
At a glance
| Diameter | 0.06 light-years |
|---|---|
| Mass | 1.99 × 10⁴¹ kg |
| Diameter compared with Earth | 4.6 × 10⁷ × Earth |
| Distance | 5.8 billion light-years |
| Cluster | Phoenix Cluster |
| Certainty | Indirect estimate |
Good to know
- Its cluster forms stars at hundreds of times the usual rate for such systems.
- The mass comes from scaling relations, not from watching stars orbit, so it could be considerably lower.
- If the estimate holds, its event horizon would be as wide as about 65 Solar Systems laid end to end.
- Next smaller: TON 618 · 0.04 light-years
- Next larger: Oort Cloud · 3.16 light-years