Since its founding in 1911, the American Association of Variable Star Observers (AAVSO) has coordinated, collected, evaluated, analyzed, published, and archived variable star observations made largely by amateur astronomers and makes the records available to professional astronomers, researchers, and educators.
The apparent magnitude of a celestial object is a number that is a measure of its brightness as seen by an observer on Earth.
A Cepheid variable is a type of star that pulsates radially, varying in both diameter and temperature and producing changes in brightness with a well-defined stable period and amplitude.
A constellation is a group of stars that are considered to form imaginary outlines or meaningful patterns on the celestial sphere, typically representing animals, mythological people or gods, mythological creatures, or manufactured devices.
Crux is a constellation located in the southern sky in a bright portion of the Milky Way.
A star is type of astronomical object consisting of a luminous spheroid of plasma held together by its own gravity.