Gamma rays are high-energy photons with energies ranging from 10 MeV to 100 GeV.

Supernovae, active galactic nuclei, and gamma-ray bursts are all known to emit gamma rays.

In supernovae, gamma rays are primarily produced by the radioactive decay of short-lived isotopes synthesized during the explosion.

Active galactic nuclei are powered by the accretion of matter onto a supermassive black hole at their centers, which leads to the emission of gamma rays.

Gamma-ray bursts are extremely energetic explosions that typically last for a few milliseconds.

The leading theory for the origin of gamma-ray bursts is the merger of two neutron stars or a neutron star and a black hole.

The Fermi Gamma-ray Space Telescope is a NASA mission dedicated to studying gamma rays from celestial sources.

Gamma rays are detected using scintillation detectors, which convert the energy of gamma rays into light signals.

Observing gamma rays from Earth is challenging due to atmospheric absorption, background radiation, and instrumental limitations.

Studying gamma rays allows astronomers to understand the most energetic phenomena in the universe, probe extreme environments, and study the evolution of galaxies.

The Sun is the closest gamma-ray source to Earth, emitting gamma rays during solar flares.

GRB 080319B, also known as the 'Monster Burst', is the brightest gamma-ray burst ever recorded.

Gamma rays can be used to probe the distribution of dark matter by studying the gamma-ray emission from galaxies and clusters of galaxies.

Gamma rays can be used to probe the cosmic microwave background, study the formation of the first stars and galaxies, and reveal the properties of the early universe.

The future of gamma-ray astronomy involves the development of more sensitive gamma-ray telescopes, exploration of new energy ranges, and multi-wavelength observations.