Gamma ray telescopes use special detectors to measure gamma radiation from stars. Unlike conventional telescopes, gamma ray telescopes don’t take pictures or use optics. Instead, they create maps of gamma sources based on where astronomers point them. The data gathered provides a unique view of the universe.
Because visible light represents a small portion of the electromagnetic spectrum, astronomers started using other instruments to observe and measure the universe. At the far end of the spectrum, radio telescopes detected unseen radiation from galaxies and discovered quasars. As rocketry began to evolve, astronomers built special telescopes to observe infrared radiation from stars and galaxies above the Earth’s atmosphere. X-ray and gamma ray telescopes followed in the early 1960s.
Gamma ray telescopes operate on satellites and carry special detectors tuned to measure high-energy gamma rays at various energy levels. Astronomers aim the satellite at potential gamma ray sources and map the resulting data. Sometimes, the data is filtered to remove low-level gamma radiation and reveal significant emissions. Gamma radiation coming from supernovas, hypernovas and quasars provide astronomy with valuable data about extragalactic matter under extreme conditions. Radiation from black holes and other dense objects also provide clues about the structure of the universe. A recent discovery in the Milky Way by the Fermi Gamma-Ray Space Telescope shows giant gamma ray “bubbles” emanating from a dense object, adding to evidence that a massive black hole is at the center of the galaxy.