← Back to Training
MCQIntermediateGalaxies & Extragalactic Astronomy
USAAAO — 2026 First Round
Question 3
Astronomers in the United States observe a spiral galaxy and measure its rotation curve. They find that beyond a radius r₀, the orbital speed of stars remains approximately constant at v₀. Which of the following conclusions is most accurate?
Sign in to save your progress.
Source
USAAAO 2026 First Round, Question 3. Question text, choices, and answer were transcribed from the official USAAAO exam and solutions PDFs.