What am I?
I am an imaginary line that circles the Earth, and I am represented on this flag for the country of Nauru. The narrow, horizontal, yellow stripe stands for me, the blue stands for the Pacific Ocean, and the star indicates Nauru's location in relation to me (the yellow stripe).

Looking for a Clue?
Photoperiod clues reveal which mystery sites are north and south of me -- the line that divides the globe into two hemispheres.