Unveiling the redback nature of the low-mass X-ray binary XSS J1227.0−4859 through optical observations★
Unveiling the redback nature of the low-mass X-ray binary XSS J1227.0−4859 through optical observations★
The peculiar low-mass X-ray binary XSS J12270−4859, associated with the Fermi/LAT source 2FGL J1227.7−4853, was in an X-ray, gamma-ray and optical low-luminosity persistent state for about a decade until the end of 2012, when it entered into the dimmest state ever observed. The nature of the compact object has been …