ACT Science Quiz
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EVALUATION OF MODELS, INFERENCES, AND EXPERIMENTAL RESULTS
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Astronomers observe that some stars appear to dim slightly and periodically over time. Three teams propose different explanations for the dimming.
Scientist 1: Scientist 1 proposes that the dimming is caused by an exoplanet transit. When a planet passes in front of the star relative to Earth, it blocks a small fraction of starlight, producing a regular, repeating dip. Scientist 1 predicts that the dips will occur at a constant period and have a similar depth each time, and that the star's spectrum will not change much during the dip.
Scientist 2: Scientist 2 argues that starspots (cooler, darker regions on the star's surface) rotating in and out of view cause the brightness changes. Scientist 2 predicts that the dimming will correlate with changes in spectral indicators of stellar activity and may vary in depth as spots grow and shrink.
Scientist 3: Scientist 3 suggests that clouds of dust orbiting the star intermittently block light. This could produce irregular dips, and dust would absorb more blue light than red light. Scientist 3 predicts that the star will look redder during dimming events.
On which point would Scientist 1 and Scientist 3 most likely disagree?
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