Sun dogs

I think I probably first knew the term “sun dogs” courtesy of a book by Robert Greenler entitled “Rainbows, Haloes and Glories” back in the 1980s, but it was in the Rush song Chain Lightning when I first took notice of the term and started spotting them in the sky. Sun dogs are sometimes known as mock suns or phantom suns, although the scientific term is parhelia (singular parhelion). They are an atmospheric (as opposed to astronomical) phenomenon and usually come in pairs, although often conditions mean you will only see one. Anyway, there was a single sundog visible not long after sunrise this morning, which I snapped from our bedroom window.


Sundogs are essentially bright spots (often resembling a fragment of rainbow) either side of the Sun and sometimes you will also see a luminous ring known as a 22° halo that rarely interconnects them fully. They can be seen anywhere in the world in any season and are due to the interaction of sunlight with ice crystals high in the atmosphere. You will most commonly see them when the sun is close to the horizon (after dawn and before dusk in other words), but sometimes you will ge a full halo around the sun when it is higher in the sky (Only ever seen that once, on Rhossili beach, Gower at about 2pm).

That Rush lyric:

Sun dogs fire on the horizon
Meteor rain stars across the night
This moment may be brief
But it can be so bright