Photometry: Measuring Brightness of Cosmic Objects

Photometry is the science of measuring how bright celestial objects appear.
Ancient astronomers like Hipparchus first classified stars by brightness.
Modern photometry uses precise detectors to measure light in different wavelengths.
It helps determine a star’s luminosity, temperature, and size.
Photometry is essential for studying variable stars that change brightness over time.
Exoplanet transits are detected when a star dims slightly as a planet passes in front.
Supernova brightness curves reveal their distances and help measure cosmic expansion.
Instruments like CCDs (charge-coupled devices) revolutionized accuracy in photometry.
Space missions like Kepler and TESS rely heavily on photometry to discover new worlds.
By tracking brightness, photometry turns tiny flickers of starlight into cosmic discoveries.