ARIES-led decade-long study of blazar OJ 287, a binary supermassive black hole
A study coordinated by ARIES, Nainital, with 106 scientists from 18 countries, tracked the blazar OJ 287 from 2015 to 2025. OJ 287, about 4 billion light years away, has two supermassive black holes in a 12-year orbit. The study estimated the central black hole at no less than 3.89 billion solar masses.
- Object
- OJ 287, a blazar
- Distance
- ~4 billion light years
- System
- two supermassive black holes, 12-year orbit
- Study period
- 2015-2025
- Lead
- ARIES, Nainital (DST)
- Main BH mass
- ≥ 3.89 billion solar masses
Blazar OJ 287: what happened?
Most galaxies have one giant black hole at the centre. OJ 287 seems to have two orbiting each other, which makes it a natural lab for gravity and jets.
- A multi-institutional study coordinated by ARIES, Nainital (DST) tracked the brightness and colour of blazar OJ 287 over 10 years [PIB].
What is a blazar?
- A galaxy core whose jet of plasma, moving at nearly the speed of light, points almost straight at Earth, so it looks very bright and changes fast across radio to gamma rays.
- OJ 287’s double-peaked brightening every 12 years was found in 1988 by Finnish scientists using records back to 1880.
Why does Blazar OJ 287 matter?
- Science: Data useful for multi-messenger astronomy, including gravitational waves.
- India: Indian institute leading a global team.
What can Prelims ask on Blazar OJ 287?
- ARIES is in Nainital, Uttarakhand (DST autonomous institute).
- OJ 287: binary black hole, 12-year cycle.
- Blazar jets point toward Earth.
How to use this in Mains
If asked: What is the significance of long-term astronomical observations for understanding black holes? (GS-III)
Quote: “OJ 287, about 4 billion light years away, has two supermassive black holes in a 12-year orbit.”
Use it: Use as a crisp factual example in a science answer.
Exam angle
Prelims: space science terms. · Mains: limited.
Practice MCQs
Original practice questions (not PYQs).
ARIES, which led the OJ 287 study, is located in
Answer (b) & explanation
PIB, 6 Oct 2026.
A blazar is best described as
Answer (b) & explanation
PIB, 6 Oct 2026.
Questions students ask about this
What is OJ 287?
A blazar about 4 billion light years away with two supermassive black holes orbiting each other every 12 years.
Which Indian institute led the study?
Aryabhatta Research Institute of Observational Sciences (ARIES), Nainital.
What is a blazar?
An active galaxy whose jet points nearly toward Earth, making it bright and highly variable.
Keep studying
Go deeper
Official source: PIB, Ministry of Science & Technology: Decade of cosmic flickering reveals clues about OJ 287, 6 Oct 2026
facts from cited sources only; faculty review pending