All currently known exoplanets with measured projected obliquities, as taken from the TEPCat catalogue (Southworth 2011). MASCARA-4 b is shown as a blue star. This further emphasises the trend that those planets orbiting hot stars have a larger probability of being in a mis-aligned orbit. The grey shaded regions denote what is considered to be a retrograde planet, with projected obliquity 112.5° ≤|λ|≤ 247.5°.