2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/101389A new derivation of the relativistic aberration formula for a plane-polarized light wave is presented that does not require any use of the Lorentz transformation. The method is based on a modification of the Huygens-Fresnel principle to include the relativistic effects introduced by the relative motion between the observer and the emitter. The derivation clearly shows that the aberration formula is a direct consequence of the relative simultaneity.10 pages, 4 figures, LATEX, a thorough revision of the first part of the older version; the second part that deals with aberration of a beam will be completely revised and published as a separate paperOpticsAstrophysicsClassical Physicstext