The estreleira is the flag used by Galician nationalists[1][2] of left-of-centre to far-left ideological allegiance.

This flag merges the flag of Galicia (a blue band on a white background) with a red star (a symbol of communism/socialism created in the Soviet Union in the early 20th century).

The estreleira flag was created by communist activists of the UPG (Unión do Povo Galego) in the 1960s, correlating the red star to the stars in the flags of many Socialist countries, in particular Yugoslavia.

All the nationalist left-wing political parties of Galicia (BNG, AGE, FPG, CERNA, Nós-Unidade Popular, Causa Galiza, etc) use the Estreleira flag as a party symbol.

It doesn't have exact dimensions standardised, and the red star in the middle sometimes goes aligned with the blue band.