If you live at 20° North latitude, the star that passes closest to your zenith (the point directly overhead) on its daily path through the sky is Polaris, the North Star.

Here's why:

* Earth's Tilt: The Earth is tilted on its axis at approximately 23.5°. This tilt is what causes seasons.

* Celestial Poles: Because of the Earth's tilt, there are points in the sky called the celestial poles, which correspond to the Earth's poles. The North Star (Polaris) is very close to the North Celestial Pole.

* Zenith: Your zenith is the point directly overhead, and its location in the sky is determined by your latitude.

* Latitude and Polaris: Since Polaris is very close to the North Celestial Pole, the angle between Polaris and your horizon is roughly equal to your latitude. If you're at 20° North, Polaris will be about 20° above your horizon, and it will appear to circle the North Celestial Pole very close to your zenith.

It's important to note that Polaris is not perfectly aligned with the North Celestial Pole, but it's very close. This means that while Polaris will be closest to your zenith, it won't actually pass directly through it.