(physics) The emission of electrons from a material when exposed to X-rays.

(astronomy) An observational branch of astronomy, which deals with the study of X-ray emission from celestial objects.

(astronomy) An instrument that detects X-rays originating from outside the Earth's atmosphere.

plural of X-ray therapy

plural of X-ray spectrometer

(astronomy) A binary star system in which one star of the pair is an optically invisible X-ray source.

(astronomy) A flash of gamma rays that seem to originate from a random point in the sky; their most likely sources are believed to be supernova explosions of a very massive stars and mergers of neutron stars.

plural of X-ray diffraction

plural of Blu-ray Disc

An optical disc storage medium used for data and video, introduced in 2006, having the same physical dimensions as a CD or DVD but greater storage capacity.