Photometry (astronomy)
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In astronomy, photometry, from Greek photo- and -metry, is a technique used in astronomy that is concerned with measuring the flux or intensity of light radiated by astronomical objects. This light is
Kepler Mission space photometer
AERONET photometer
Variable star
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A variable star is a star whose brightness as seen from Earth changes systematically with time. This variation may be caused by a change in emitted light or by something partly blocking the light, so
Photometry (astronomy)
…a spectrophotometer and observes both the amount of radiation and its detailed spectral distribution. Photometry is also used in the observation of variable stars, by various techniques such as, differential photometry that simultaneously measures the brightness of a target object and nearby stars in the starfield…
Comparison of VLT-SPHERE images of Betelgeuse taken in January 2019 and December 2019, showing the changes in brightness and shape. Betelgeuse is an intrinsically variable star.
A photogenic variable star, Eta Carinae, embedded in the Carina Nebula
Herbig Ae/Be star V1025 Tauri and surrounding molecular nebula
Artist's impression of a large dust cloud in the envelope of R CrB