Perihelion and aphelion refer to the position of a planet relative to it’s parent star.

When the planet in it’s orbit is at the position closest to it’s parent star it is said to be at the perihelion . When the planet in it’s orbit is at the position farthest to it’s parent star it is said to be at the aphelion .

Perihelion and aphelion refer to the position of a planet relative to it’s parent star.

When the planet in it’s orbit is at the position closest to it’s parent star it is said to be at the perihelion . When the planet in it’s orbit is at the position farthest to it’s parent star it is said to be at the aphelion .