The latitude of a place was obtained by subtracting the declination of a star from its zenith distance, the observed star was between

Answer: Option C

Correct Answer: Option C: Equator and Zenith

Explanation:
Latitude (φ): Latitude measures how far north or south a location is from the Earth's equator, expressed in degrees (0° at the equator, 90° at the poles).

Declination (δ): Declination is similar to latitude but for celestial objects, measuring how far a star is from the celestial equator. A star on the celestial equator has $\delta =0^{\circ }$, while a star at the celestial north pole has $\delta =+90^{\circ }$.

Zenith Distance (z): Zenith distance is the angle between a star and the observer's zenith (the point directly overhead). A star at the zenith has $z=0^{\circ }$, while a star on the horizon has $z=90^{\circ }$.

Formula:
The given formula is:
$$\varphi =z-\delta$$
This formula applies when the observed star is positioned between the observer's zenith and the equator.

Reason:
- Zenith distance is measured from the zenith downward.
- Declination is measured from the celestial equator.
- The subtraction only works when the star is south of the zenith, which means the star lies between the equator and the zenith.

Conclusion:
The correct answer is Option C: Equator and Zenith because the given formula holds only in this case.