Difficulty: Easy
Correct Answer: 1°
Explanation:
Introduction / Context:
Polaris, commonly known as the Pole Star, lies close to the north celestial pole and is a crucial reference for astronomical observations, surveying, and navigation. Although it appears nearly fixed, it actually traces a small circle around the pole as Earth rotates. Knowing the approximate radius of this circle helps observers anticipate its slight nightly motion and plan precise pointing or latitude checks.
Given Data / Assumptions:
Concept / Approach:
The angular radius of Polaris’s apparent circle equals its angular distance from the pole (90° minus Polaris’s declination). Modern values place Polaris within about 1° of the pole, historically hovering somewhat under a degree; for standard surveying/astronomy exams, this is commonly rounded to approximately 1°.
Step-by-Step Solution:
Verification / Alternative check:
Star charts and almanacs show Polaris within roughly a degree of the pole in recent centuries, confirming the conventional approximation used in fieldwork.
Why Other Options Are Wrong:
Common Pitfalls:
Assuming Polaris is exactly at the pole (radius 0°) or overestimating the radius by several degrees; neglecting that the exact value changes slowly over centuries due to precession.
Final Answer:
1°
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