Bibcode
                                    
                            Collados, M.; del Toro Iniesta, J. C.; Vazquez, M.; Woehl, H.
    Referencia bibliográfica
                                    Solar Physics (ISSN 0038-0938), vol. 117, no. 1, 1988, p. 199-202.
Fecha de publicación:
    
                        3
            
                        1988
            
  Número de citas
                                    3
                            Número de citas referidas
                                    3
                            Descripción
                                    The age dependence of the recently described asymmetry of penumbrae of
large stable sunspots was analyzed. Young sunspots showed shorter
eastern penumbrae, which differed by a maximum of + or - 10 percent from
their mean width. For older sunspots the western penumbrae became
smaller than the mean penumbra, reaching differences of 20 percent for
spots of two months in age.