[amp_mcq option1=”Horizon and equator” option2=”Equator and zenith” option3=”Zenith and pole” option4=”Pole and horizon” correct=”option2″]
The correct answer is: B. Equator and zenith.
The declination of a star is its angular distance from the celestial equator, measured north or south. The zenith distance of a star is the angle between the star and the zenith, the point directly overhead. The latitude of a place is the angle between the Earth’s equatorial plane and the vertical at that place.
If the latitude of a place is obtained by subtracting the zenith distance of a star from its declination, then the observed star must be between the equator and the zenith. This is because the zenith distance of a star is always greater than or equal to its declination, and the latitude of a place is always less than or equal to 90 degrees.
Option A is incorrect because the horizon is the lowest point in the sky, and the observed star must be above the horizon in order to be seen. Option C is incorrect because the pole is the highest point in the sky, and the observed star must be below the pole in order to be seen. Option D is incorrect because the observed star must be between the equator and the zenith, and the pole is not between the equator and the zenith.