RRI Study Finds Accretion Disk Around Pulsar Centaurus X-3

Researchers at the Raman Research Institute (RRI), an autonomous institution of the Department of Science and Technology, have shown that Centaurus X-3, among the brightest X-ray pulsars known, is pulling in matter through an accretion disk. In systems of its kind that route is uncommon, and the finding was put out on 21 October 2026. The team was led by Kinjal Roy, a researcher at the institute.

What kind of object it is

An X-ray binary pulsar is a pair: a pulsar, which is a neutron star with an extremely strong magnetic field, locked by gravity with an ordinary star. A neutron star packs about as much material as the Sun into a ball roughly the width of Bengaluru. The pulsar's gravity strips matter from its partner, and as that matter falls in, X-rays pour out.

The system in figures

How the structure was traced

Radiation leaving the magnetic poles of a pulsar is called the primary emission. Part of it strikes nearby structures, such as the surface of the companion star or the wind blowing off it, and is thrown back as secondary emission. Because these binaries lie so far away that a telescope sees only a point, that secondary light is the main handle scientists have on the shape of the surroundings.

The RRI team examined four secondary emission lines closely. The pattern showed that whatever produced the changing lines had to be turning along with the pulsar itself. Working back from that clue, Kinjal Roy identified the accretion stream, the channel that carries matter from the disk towards the magnetic poles. When the stream passes between the pulsar and the observing satellite, the direct light dips while the reflected light rises.

Why the result matters

A stream of that kind cannot exist without a disk feeding it, so the disk must be there. In high-mass X-ray binaries matter is usually captured straight from the companion's stellar wind, and a disk is not expected. Models of this system will therefore have to be rewritten to account for radiation from the disk, and the work also sharpens the broader picture of how binary pulsars behave.