NICER Data on High-Mass Binary (IMAGE) NASA/Goddard Space Flight Center Caption GX 301-2, a high mass X-ray binary, is a system in which a massive, aging star's dense wind is drawn toward the strong gravity of a neutron star. The column of falling material emits X-rays, dominated at certain times by the fluorescent glow of atoms of heavy metals such as iron and nickel. NICER's X-ray detectors measure the energies (or colors) of X-ray photons - the technique of spectroscopy -- to determine the chemical makeup and density of the accreting material in this 1,200-second exposure. Credit NASA Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.