2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/209526We propose a scenario that involves a stationary observer who detects a point like source of light moving with constant velocity at a constant altitude, using a telescope and a frequency-meter. We derive a formula for the angular velocity at which we should rotate the axis of the telescope and a formula that relates the proper period at which the source emits successive wave crests and the proper period at which the stationary observer receives them5 pages, 5 figuresGeneral Physicstext