Chinese astronomers investigated the spectral and temporal properties of a black hole X-ray binary system known as SLX 1746-331, during its recent outburst. Results of the study, published in The Astrophysical Journal Letters, could help us better understand the nature of this system and its behavior.

X-ray binaries are composed of a normal star or a white dwarf transferring mass onto a compact neutron star or a black hole. Based on the mass of the companion star, astronomers divide them into low-mass X-ray binaries (LMXBs) and high-mass X-ray binaries (HMXBs).

SLX 1746-331 is a transient black hole LMXB at a distance of about 35,200 light years, discovered in 1985. After a 13-year-long period of quiescence, it entered an outburst in 2023, which peaked on March 14.