how can i fill this shape?

hi i need to fill this shape but i can't the shape is made with a '*' so the fill function doesn't really help me with this any suggestions?

my code:

alpha=1;
xi=0.5;
l=4;
R=2000; % the resolution
phi=1:R;
for i=1:R;
r(i)=alpha*(1+xi*cos(l*phi(i)));
end
[X,Y]=pol2cart(phi,r);
plot(X,Y,'.')
axis equal
grid on
title('\bf The Shape')
xlabel('X Coordinate')
ylabel('Y Coordinate')