• A spectrograph is an machine that can separate an incoming electromagnetic wave into a frequency spectrum and record or map the spectrum. Nobel Prize laureate Sir J.J.Thomson created the first versions of this machine in the beginning of the 20th century. Later, Francis W. Aston improved the apparatus and in 1922 also received the Nobel Prize in Chemistry. Spectrographs have since been widely used in biochemistry, astronomy, and physics, contributing to important scientific breakthroughs.
  
  

Isotopes

• Isotopes are one of two atoms from the same element, thus having the same atomic number but with different mass numbers. Using a mass spectrograph, Francis W. Aston established the existence of isotopes, thereby disproving John Dalton's ideas that all atoms from the same element are identical. He identified isotopes of neon and chlorine, using a large mass spectrograph that he built.
  
  

Electron

• Sir J.J.Thomson discovered the electron, a subatomic particle with a negative electric charge, thanks to his experiments with the spectrograph from the late 19th to the early 20th centuries. This important discovery contributed decisively to the development of atomic physics and contributed conclusive evidence about the small-scale structure of matter.
  
  

HARPS Planets Discovery

• HARPS, which stands for High Accuracy Radial Velocity Planet Searcher, is a spectrograph located in La Silla, Chile. In 2009 the spectrograph detected 32 new planets out of the solar system, according to "Science Daily." As of October, 2009, HARPS has spotted more than 75 of the 400 exoplanets now known. Spectrographs analyse the electromagnetic spectrum emitted from celestial bodies, also allowing astronomers to measure properties such as velocity and temperature.