Key Information
OJ 287
| Type | Galaxy and Supermassive Black Hole Binary |
| Diameter (Galaxy) | At least 90,000 light years |
| Distance | 4 billion light years |
| Total Stars | Unknown |
| Size of Black Holes | 18.35 billion (A) and 150 million (B) |
| Date of Discovery | Around 1965 to 1971 |
Learning Point
- OJ 287 is a galaxy located 4 billion light-years away famous for containing a Supermassive Binary Black Hole (SMBHB) system. The primary black hole is one of the largest known, weighing around 18 billion times the mass of the Sun, and is orbited by a smaller companion black hole. This intense gravitational pairing causes the system to emit dramatic, predictable bursts of light every 11 to 12 years. These enormous flashes help in confirming complex predictions made by Einstein’s theory of General Relativity.
Project
- Draw a diagram of OJ 287.
- Overview
- Animation
Location
| Location | Cancer constellation |
Fun Facts
- The larger black hole in the pair is absolutely enormous, weighing about 18 billion times the mass of our own Sun! It’s one of the biggest known black holes in the universe.
- This galaxy sends out an enormous burst of light that we can see from Earth almost like clockwork, happening once every 11 to 12 years.
- The famous flashes happen when the smaller black hole swings in close and punches through the massive ring of gas (the accretion disk) surrounding the bigger black hole. It punches through twice per orbit!
- When OJ 287 flares, its burst of light is so incredibly powerful that it shines brighter than a trillion Suns—more light than the entire Milky Way galaxy gives off!
- The two black holes are slowly spiraling closer together. Scientists predict they will eventually crash and merge into one giant, monster black hole in about 10,000 years!
Past Lessons
| 242 | December 1, 2025 | (North America) |