Sena Zutic (Member 5,882) spotted this parhelion, or sun dog, over Croatia. Although the Sun is not visible in the close-up of this light effect, we know exactly where it would have been: level with Sena’s sun dog, out of frame to the right.
Caused by sunlight bending, or refracting, as it shines through the side faces of cloud ice crystals that are tiny and in the shape of hexagonal plates, sun dogs can appear to either side of the Sun. If they have a reddish edge, like Sena’s does, this is always on the side that’s towards the Sun. The ice crystals causing this sun dog were in Cirrus uncinus clouds, which look like streaks hooked at one end. Also present – and seriously upstaged by them – are Cirrostratus, the fuzzy grey layer beyond, and the two darker blobs of Altocumulus in shadow.