Gravitational redshift, used for GPS, detected in double star system

An effect predicted by Albert Einstein's Theory of Relativity called gravitational redshift has been detected in a star system 29,000 light years from Earth. Gravitational redshift is used to deliver accurate data for GPS. -- Effect predicted by Albert Einstein spotted in a double-star system: https://www.space.com/einstein-gravitational-redshift-observed-double-star-system.html Credit: NASA/CXC/A. Hobart