Adopted model of Betelgeuse. The molecular shell is shown approximately to scale with respect to the continuum. The right part of the shell is omitted to show the continuum without line absorption. The cool molecular layer located around the star and shell is not represented. The position angle of the polar axis is represented according to the best fit model. The (x,y) coordinates are the sky angular coordinates of the reference frame; the z-axis is pointing toward the observer.