What analysis provides far more conclusive evidence than brightness or angular size for confirming a distant galaxy's nature?

Answer

Analyzing the spectrum of that light

Analyzing the spectrum of the light reveals the object's chemical makeup and motion, offering more conclusive evidence than just brightness or size.

What analysis provides far more conclusive evidence than brightness or angular size for confirming a distant galaxy's nature?

#Videos

How Do Astronomers Locate Distant Galaxy Clusters? - YouTube

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