How Do Astronomers Know That the Nuclei of Some Galaxies

question 28

Multiple Choice

How do astronomers know that the nuclei of some galaxies are active?

• A) Their nuclei are much brighter than expected.
• B) The orbits of stars near the center of the galactic nuclei are faster than expected.
• C) The luminosity of the nuclei varies over time.
• D) The color of the nuclei is different than expected.

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Definitions:

Power Analysis

A statistical technique used to determine the sample size required to detect an effect of a given size with a certain degree of confidence.

Empirical Reasoning

The process of drawing conclusions based on observation or experience rather than theory or pure logic.

Experimental Group

The group in an experiment that receives the treatment or intervention, allowing researchers to measure the effect of that intervention.

Power Analysis

A statistical method used to determine the sample size required to detect an effect of a given size from a statistical test.