Last Saturday while on a hike with the Ausbon Sargent Land Preservation Trust on a newly conserved property in Sunapee, I spotted a 22 degree halo around the sun. The folks I was walking with called it a sun dog, a common error. Technically sun dogs are the two bright and often colorful spots that sometime appear along or near the halo on each side of the sun. Sun dogs can appear without a visible halo. In this case there was a halo without visible sun dogs. Both are caused by the refraction of light from plate-shaped hexagonal ice crystals falling through the atmosphere.
You can see photos of many different and interesting things in the sky HERE.