Hot dog, I found the perfect pup!

This dog won’t hunt. It also won’t shed, drool or bark, and never has to be taken out for a walk. For a cat lover like me, it is the perfect pooch. Sundogs are my favorite canine companions.

Sundogs live in the sky. They appear as two bright spots equidistant (and at the same elevation) on the left and right of the sun, usually along the perimeter of a halo circling the sun. Since they resemble mini suns, sundogs are also referred to as mock suns or phantom suns. Scientists call them parhelia, which means “besides the sun” in Greek.

The Greeks were more accurate than they probably realized. Besides the sun, there are things in the sky that create sundogs. High in the atmosphere and especially associated with cirrus clouds, hexagonal ice crystals act as prisms for the sun’s light, and use refraction (or the bending of light) and reflection to harness light and produce color. 

These colors vary depending on location. Closest to the sun, look for subtle red color, and as your eye moves toward the outside of the sundog (away from the sun), the colors meld into oranges, then through the blues and finally to white on the outermost edges.

This celestial phenomenon is not rare and can be seen anywhere at anytime, though it is most often viewed when the sun is lower on the horizon. Sundogs are also more frequently seen in the winter months than during other seasons. 

Sundogs are usually associated with halos, which are rings of light around the sun or moon. If you see a sundog, look for a full light or subtle rainbow ring around the sun. Both sundogs and halos are formed in similar ways, but vary due to the orientation of those hexagonal ice crystals. Sundogs are found when the ice crystals are vertically aligned, while the halo is the result of random crystal orientations.

Dogs also appear during the night, but those hounds are called moon dogs, mock moons, or paraselene. These are less common than their daytime counterparts.

Humans have long been observing these sky happenings. Greek philosopher Aristotle wrote that one day “two mock suns rose with the sun and followed it all through the day until sunset.” He further observed that they were always on the sides and never above or below the sun. Again, the Greeks got it right.

Another Grecian, the poet Aratus, was an early proposer that these “sky lights” predicted weather, indicating wind, rain or an approaching storm. And diviner Artemidorus suggested that they were celestial deities.

Shakespeare’s observation of these puppies should not be left out. In King Henry VI, there’s a dialog about these cosmic constructions:

EDWARD: Dazzle mine eyes, or do I see three suns?

RICHARD: Three glorious suns, each one a perfect sun; . . . See, see! they join, embrace, and seem to kiss . . . Now are they but one lamp, one light, one sun.

EDWARD: ‘Tis wondrous strange, the like yet never heard of. . . Whate’er it bodes, henceforward will I bear upon my target three fair-shining suns.

It’s easy to see how celestial aberrations like sundogs (and halos) seemed miraculous and perhaps prophetic to people back in olden times, but they were barking up the wrong tree if they thought these dogs represented a stigma, or, for that matter, even an astigmatism: they just display some super cool celestial science.

Suzan Bellincampi is director of the Felix Neck Wildlife Sanctuary in Edgartown, and author of Martha’s Vineyard: A Field Guide to Island Nature.