Apparent motion of Polaris — direction at eastern elongation At the instant of eastern elongation in its small diurnal circle around the north celestial pole, in which direction does the pole star (Polaris) appear to move?

Introduction / Context:
Stars appear to move in circles around the celestial poles due to Earth’s rotation. Polaris lies close to the north celestial pole and traces a small circle (of radius ≈ 1°) about it. Understanding instantaneous motion at elongation points helps in precise astronomical observations and instrument checks.

Given Data / Assumptions:

• Northern hemisphere perspective with counterclockwise apparent rotation about the pole.
• Eastern elongation is the point of the small circle farthest to the east of the pole.

Concept / Approach:
At the easternmost point of a counterclockwise circular path, the instantaneous motion is tangential and directed upward on a standard sky diagram, that is, toward the north (increasing altitude) for Polaris. Conversely, at western elongation, the motion is toward the south (decreasing altitude). “Eastward” or “westward” at elongations would imply radial motion toward/away from the pole, which is not correct for the tangential diurnal motion.

Step-by-Step Solution:

Verification / Alternative check:
Star-trail diagrams and planetarium software confirm the motion sense: northward at eastern elongation and southward at western elongation for Polaris.

Why Other Options Are Wrong:

• Eastward/westward: do not represent the tangent direction at elongation.
• Southward: applies at western elongation, not eastern.

Common Pitfalls:
Confusing cardinal directions on the sky dome with azimuthal directions on the ground; forgetting the counterclockwise sense around the north pole.

Final Answer:
Northward