Relativistic Aberration Effect in Astrophysics and Cosmology
  Relativistic aberration influences apparent luminosities of objects moving with relativistic relative velocities. The superluminosity or dimming of incoming or receding jets ejected from Active Galactic Nuclei is believed to be the manifestation of the effect. Redshifted cosmological objects, such as high-z galaxies and supernovae in high-z galaxies, are also subjected to luminosity dimming due to relativistic aberration, although the correcting terms encompassing spectral redshift and time dilation are used to scale the observed magnitudes in the restframe template. The Universe's expansion results in elongation of distances to the objects from the moment of emission to the present time related to the z = 0 local space; this elongation is equal to the apparent increase of the distance from the apparent size to the restframe distance in the theory of special relativity due to the effect of relativistic aberration. Contrary to the standard Big Bang model with stationary space, the effect of relativistic aberration zeroes in the expending space model; if local spaces and local objects expand together with the Universe, the luminosity distances to high-redshifted objects appear to be smaller then in the Big Bang model. 
Oleg Semyonov