Centaurus X-3 is a high-mass X-ray binary containing a highly magnetised neutron star and a companion star with more than ten times the Sun’s mass. Located about 24,000 light-years away in the constellation Centaurus, it is among the brightest X-ray pulsars. In October 2026, researchers at the Raman Research Institute (RRI), Bengaluru, led by Kinjal Roy, reported findings on its accretion dynamics.
Centaurus X-3 and X-ray binaries
An X-ray binary consists of a compact object, such as a neutron star or black hole, and a companion star from which it receives matter. A high-mass X-ray binary has a massive companion star. Centaurus X-3 is also an eclipsing binary, in which the companion periodically passes in front of the X-ray source as seen from Earth. The system was discovered by the Uhuru X-ray observatory in 1971 and was the first X-ray pulsar identified.
Accretion and pulsar timing
Accretion is the process by which a compact object gathers gas from a surrounding star or its environment. In a rotating neutron star, magnetic fields can channel incoming matter towards the magnetic poles, producing X-ray pulses. RRI researchers reported that Centaurus X-3 accretes matter through a structured accretion disk and a co-rotating accretion stream. The study also reported stable disk accretion alongside secular spin-up and orbital decay. Pulse phase-resolved spectroscopy analyses X-ray spectra at different phases of a pulsar’s rotation and can examine changes in the emitting system.
Observations of Centaurus X-3
A 2024 study used nearly 14 years of MAXI/GSC data to examine X-ray absorption in Centaurus X-3 and found that photoelectric absorption varies asymmetrically across the orbit. MAXI is an X-ray instrument on the International Space Station, and GSC stands for Gas Slit Camera. A March 2026 study used XRISM data to examine fluorescing matter in the system. It reported energy shifts in Fe-K fluorescence lines associated with low ionisation. XRISM, the X-Ray Imaging and Spectroscopy Mission, was launched in 2023.
Important Facts for Exams
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- Centaurus X-3 was discovered by the Uhuru X-ray observatory in 1971.
- An X-ray pulsar is a rotating neutron star that emits pulsed X-ray radiation.
- MAXI is installed on the Japanese Experiment Module of the International Space Station.
- XRISM is an X-ray astronomy mission launched in September 2023.
