The yellow rhombus and green background originated in the imperial flag, in which they represented the House of Habsburg-Lorraine and the House of Braganza, respectively.^[1] The blue circle represents the sky and stars over Rio de Janeiro on the morning of 15 November 1889, as viewed by a hypothetical observer external to the celestial sphere. Each star represents a federative unit as defined by law, and new stars are included or removed with the creation or fusion of states.^[2] The lone star above the white band is Spica (α Virginis) and represents the state of Pará, which had the largest amount of land north of the Equator in 1889.^[3]