Grating in shipping container (IMAGE) University of Leicester Caption The optical element for SIRIUS, a reflection grating, that focusses and disperses the light into a spectrum. Credit University of Leicester Usage Restrictions Use only with credit. License Original 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.