%0 Journal Article %T Transport in Astrophysics: IV. Anomalous Redshift in the Solar System %A Lorenzo Zaninetti %J International Journal of Astronomy and Astrophysics %P 61-73 %@ 2161-4725 %D 2023 %I Scientific Research Publishing %R 10.4236/ijaa.2023.132004 %X The anomalous redshift on the sunĄ¯s limb and that measured by Pioneer-6 are interesting for the process of absorption of light and the spatial density of matter around the sun. Here we derive a 3D solution for the diffusion equation in the case of the steady state, which is then adopted as the density of the ionized matter around the sun. In order to deal with the observed lightĄ¯s intensity, two integrals along the line of sight are evaluated. Alternatives to the Doppler shift have been considered as mechanisms: a thermal model, a plasma effect, the interaction of a low density electromagnetic wave with an electron and the interaction of light with a low density Fermi gas in standard QED. These four models are compared in the case of the Pioneer-6 signal. %K Particle Diffusion %K Random Walks %U http://www.scirp.org/journal/PaperInformation.aspx?PaperID=125466