Question

part (e)
which of these statements about polaris is correct?
its position in the sky changes very significantly over the course of the night.
it is located 90° around the horizon.
it is located at the zenith.
it is located at a declination of about +90°.
it is the visually brightest star in the sky.

Explanation:

1. Analyze each option:

• "Its position in the sky changes very significantly over the course of the night": Polaris is the North Star, and it is nearly stationary in the night sky (due to its alignment with Earth's axis), so this is incorrect.
• "It is located 90° around the horizon": Polaris is near the celestial north pole, not related to being 90° around the horizon, so this is incorrect.
• "It is located at the zenith": The zenith is directly overhead, and Polaris is only at the zenith for observers at the North Pole. For most observers, it is at some altitude above the northern horizon, so this is incorrect.
• "It is located at a declination of about +90°": Declination measures the angular distance from the celestial equator. The celestial north pole has a declination of +90°, and Polaris is very close to the celestial north pole, so its declination is about +90°, this is correct.
• "It is the visually brightest star in the sky": The brightest star in the sky is Sirius, not Polaris, so this is incorrect.

Answer:

It is located at a declination of about +90°.