A Spectrum of the Sun Shows Many Dark Features because of Various Chemical Elements in Sunlight (image) University of Sydney Share Print E-Mail Caption HERMES, the new spectrograph built at the AAO, uses volume phase holographic (VPH) gratings to provide various optimized spectra in blue, green and red light and a fourth band in infra-red light. HERMES spectra allows astronomers to study the chemical makeup of stars to understand their formation and evolution. A spectrum of the Sun shows many dark features because of various chemical elements in sunlight. Credit N.A. Sharp, NOAO/NSO/Kitt Peak FTS/AURA/NSF. Usage Restrictions Must credit Share Print E-Mail 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.