Stellar aberration may be caused by mechanism as follows. From outer space, a light ray of a star is entering atmosphere of the earth. Angle of refraction may be affected by the motion of the earth (it's "drag" by moving medium). If so, the result of Airy experiment (aberration with a telescope filled with water : 1871) may be explained. Analogy with rain-drop may be unsuitable.

In the outer space, the object lens of telescope may "drag" (as a moving medium) the ray (path) of star light. Then, aberration occurs (mechanism is different from the one that occurs in the atmosphere). In the outer space, aberration may occur about hollow tube also (photons pass through as rain drops).

In outer space, the object lens of telescope may "drag" the ray of star light. If it's actual, the value of aberration may be larger (because in the glass, the light speed is slow). It looks a revival of Airy's telescope.