What is a “Sun Dog”? And Why Are We Seeing One Over Cheyenne?

It's cold enough for SUN DOGS.

Folks all over are taking photos of this rare and wonderful event.

A sun dog (or sundog) or mock sun, is also called a parhelion (plural parhelia) in meteorology.

Two sun dogs often flank the Sun within a 22° halo.

Sun Dog? How did we end up with that name?

These halos are caused by the refraction of sunlight by ice crystals in the atmosphere.

It's really cold out this week, you might have noticed. At the same time, there is still some humidity in the air.

The sun and the cold are working with crystals of cirrus or cirrostratus clouds.

The term “parhelion” is derived from the Greek term for “beside the sun”.

OKAY great.

But what about SUN DOG? Where the heck does that come from?

WELL -- “Sun dog” is also traced back to ancient Greece with these bright spots seemingly “following” the sun (or Zeus) like a dog.

This event can also occur when the moon is bright enough on a cold night.

That's called a paraselene.

But is it called a "MOON DOG?"

Actually, yes it is.

I like the sound of Moon Dog. It's a great name.

These photos were taken by Jullia Huntington of Cheyenne, Wyoming.

Keep your eye on the sky to see it. But don't look too long.

Airplane pilots are actually warned about these things. They are bright and can really screw with a pilot's vision.

These events can look very different every time you see them.

So enjoy the variety.