Astronomy Glossary

Telescopes Equipment

Cassegrain telescopes use a primary mirror that reflects light to a convex secondary mirror, which reflects it back through a hole in the primary to a...

Stellar Objects

Cepheid variables are luminous pulsating stars with periods of 1-100 days, exhibiting a precise relationship between pulsation period and intrinsic lu...

Telescopes Equipment

Coma is an optical aberration in parabolic mirrors (like Newtonians) that makes off-axis stars appear as tiny comets pointing toward the field edge.

Solar System

Comets are icy bodies from the outer Solar System that develop spectacular tails when approaching the Sun as their ices vaporize.

Solar System

A Coronal Mass Ejection is an enormous burst of plasma and magnetic field ejected from the Sun's corona into space, carrying billions of tons of mater...

Cosmology Universe

Cosmic horizons define boundaries beyond which information cannot reach us due to finite light speed and Universe's expansion history.

Cosmology Universe

Cosmic inflation is a period of exponential expansion in the first 10^-36 to 10^-32 seconds after the Big Bang, proposed to solve several cosmological...

Cosmology Universe

The Cosmic Microwave Background is the thermal radiation from 380,000 years after the Big Bang, when Universe cooled enough for neutral atoms to form ...

Galaxies

The cosmic web is the large-scale structure of the Universe, consisting of filaments of galaxies surrounding vast empty voids, resembling a sponge-lik...