Why do astronomers use red giants as standard candles?

Answer

Their high luminosity makes them visible over great distances

Because red giants are exceptionally luminous, they are easily visible even when they are very far away. Astronomers utilize this high visibility to estimate distances to other galaxies, effectively employing these stars as standard candles to measure the vast scales of the universe.

Why do astronomers use red giants as standard candles?

#Videos

What Are Red Giant Stars? - YouTube

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