What term is used to describe astronomical objects whose known intrinsic brightness allows astronomers to calculate their distance using apparent brightness?
Answer
Standard candles
Measuring intergalactic distance relies on comparing how bright an object truly is (its absolute magnitude or intrinsic luminosity) against how bright it appears from Earth (apparent brightness). Objects that possess a reliably known, fixed intrinsic brightness are designated as standard candles. The inverse-square law of light is then applied to the discrepancy between these two brightness measurements to yield the actual physical distance to the object.
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