Astrophysics & Particle Physics-APPC 2026

Variable stars are stars whose luminosity varies over a period of time, either periodically or irregularly. These changes can arise due to intrinsic processes, such as pulsations or eruptions, or extrinsic causes, such as eclipses in a binary system. Variable stars offer invaluable information about stellar structure, evolution, and the measurement of cosmic distances.Observations of variable stars depend on photometric and spectroscopic monitoring at a range of wavelengths.

Today's surveys, e.g., the OGLE, ASAS-SN, and Gaia missions, detect thousands of variable stars, enhancing our knowledge of stellar populations and galactic structure.Hence, variable stars are active labs for investigating stellar physics, binary interactions, and cosmic distances. By studying their brightness changes, astronomers reveal the life cycles of stars and the basic processes governing their behavior throughout the universe.