The Stockholm Sun Dog on This Day in History

A painting depicting the Stockholm Sun dog, it is considered the oldest image to portray this phenomenon.

This Day in History: The sun dog phenomenon is observed over Stockholm on this day in 1535 as later depicted in the famous painting Vädersolstavlan. At the time it was considered a dark omen. A sun dog is basically an atmospheric phenomenon that is often often seen as a luminous ring or halo on either side of the sun. Sundogs can be seen anywhere in the world during any season, and they are best seen when the sun is low.

The exact etymology of sun dog largely remains a mystery. The Oxford English Dictionary states it as being "of obscure origin". In Abram Palmer's 1882 book Folk-etymology: A Dictionary of Verbal Corruptions Or Words Perverted in Form Or Meaning, by False Derivation Or Mistaken Analogy, sun-dogs are defined:
"The phenomena of false suns which sometimes attend or dog the true when seen through the mist (parhelions). In Norfolk a sun-dog is a light spot near the sun, and water-dogs are the light watery clouds; dog here is no doubt the same word as dag, dew or mist as 'a little dag of rain' (Philolog. Soc. Trans. 1855, p. 80). Cf. Icel. dogg, Dan. and Swed. dug = Eng. 'dew.'"

Perhaps one of the oldest description of a sundog comes from the ancient Greek philosopher Aristotle. Aristotle (Meteorology III.2, 372a14) notes that “two mock suns rose with the sun and followed it all through the day until sunset.” He says that “mock suns” are always to the side, never above or below, most commonly at sunrise or sunset, more rarely in the middle of the day.