Explanation:

- Aurora Borealis:

- ?? Known as the northern lights.

- Occurs in polar regions.

- Caused by charged particles from the sun interacting with Earth’s magnetic field.

- Creates splendid displays of colors in the sky.

- Star Shower:

- Refers to meteor showers, not related to polar light phenomena.

- Meteors burn up entering the Earth's atmosphere creating streaks of light.

- Active Galactic Nucleus:

- Region at the center of a galaxy.

- Emits significant amounts of radiation.

- Not related to light displays in Earth's sky.

- Star's Intrinsic Luminosity:

- Measure of the original brightness of a star.

- Not related to atmospheric phenomena.

Answer: Aurora Borealis