Indian scientists at the Raman Research Institute (RRI), an autonomous institution under the Department of Science and Technology (DST), have discovered that Centaurus X-3 — one of the brightest known X-ray pulsars — is drawing in material through an accretion disk, a behaviour considered rare for pulsars of its class. The findings were announced in an official statement on Wednesday, 21 October 2026, and were led by researcher Kinjal Roy.

What Is Centaurus X-3

Located roughly 24,000 light years away in the constellation Centaurus, Centaurus X-3 was among the very first X-ray pulsars ever identified — and the third X-ray source catalogued in its constellation. It belongs to a class called high-mass X-ray binaries (HMXBs), where the companion star is more than 10 times the mass of the Sun. An X-ray binary pulsar pairs a highly magnetised neutron star — a celestial object with the mass of our Sun compressed into a sphere roughly the size of Bengaluru — with a companion star, both locked in mutual gravitational orbit.

How the Discovery Was Made

Pulsars emit radiation from their magnetic poles — known as primary emission — which sweeps across space as the pulsar spins. This radiation also falls on nearby structures, which absorb and re-emit it as secondary radiation. The RRI team investigated four secondary emission lines in depth and found that the structure producing those varying lines must be co-rotating with the pulsar itself.

Critically, that investigation revealed an accretion stream — a channel that funnels material from the accretion disk directly toward the pulsar — as the source of the variability in those secondary lines. According to the Ministry of Science and Technology, the detection of the accretion stream constitutes direct evidence of an accretion disk around Centaurus X-3.

Why This Matters for Science

'In an X-ray binary, the pulsar's extreme gravity pulls in material ejected by its companion star, and the pulsar starts accreting material from it, shooting out X-rays in the process,' the Ministry of Science and Technology statement noted. The finding has direct implications for constructing more accurate theoretical models of the Centaurus X-3 system, which has long attracted scientific attention because of its exceptional X-ray brightness.

Beyond this single system, understanding these secondary emission structures — including their orientation and the magnetic field strengths they reveal — is expected to sharpen the broader scientific understanding of binary pulsars as a class. Notably, accretion disks in pulsars of this type are not commonly confirmed, making the RRI team's detection a significant observational result.

What Comes Next

The study is expected to serve as a template for investigating secondary emission lines in other high-mass X-ray binary systems. Researchers hope the methodology applied to Centaurus X-3 can be extended to refine models of similar pulsars, potentially resolving longstanding uncertainties about accretion geometry in X-ray binaries. The RRI, backed by the DST, continues to be a key contributor to India's growing profile in high-energy astrophysics.