|Sun dogs seen at sunset and close-up of one|
This summer I encountered my first "sun dogs." I didn't know the name for this atmospheric phenomenon at the time. It wasn't a rainbow, but rather two circular "prisms" with a halo around them to the right and left of the setting sun.
My photos here don't do it justice. I posted them online and someone clued me in to the name.
These pairs of bright spots on either horizontal side on the Sun, often co-occurring with a luminous ring/halo are called sun dogs (or sundogs, mock suns or phantom suns) but are known to scientists as parhelia (singular parhelion).
They are one kind of halo created by light interacting with ice crystals in the atmosphere. Despite that ice requirement, they can be seen anywhere in the world during any season, but they are not always obvious or bright. Sun dogs are best seen and are most conspicuous when the Sun is close to the horizon.
In searching online for the origin of this term, I found, as if often the case, that even The Oxford English Dictionary states it as being "of obscure origin." "Parahelion" if from Greek parēlion, meaning "beside the sun"; from para, meaning "beside", and helios, meaning "sun."
Here are some possible etymologies of the usage as noted in Wikipedia:
- "false suns which sometimes attend or dog the true when seen through the mist." (defined in Abram Palmer's 1882 book with a very long title, Folk-etymology: A Dictionary of Verbal Corruptions Or Words Perverted in Form Or Meaning, by False Derivation Or Mistaken Analogy
- In Scandinavia, 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."
- Alternatively, Jonas Persson suggested that out of Norse mythology and archaic names (Danish: solhunde (sun dog), Norwegian: solhund (sun dog), Swedish: solvarg (sun wolf)) in the Scandinavian languages, constellations of two wolves hunting the Sun and the Moon, one after and one before, may be a possible origin for the term.
- In the Anglo-Cornish dialect of Cornwall, United Kingdom, sun dogs are known as weather dogs and are seen as a warning of foul weather. (The weather was fine after I saw my sun dogs.) It is also known as a lagas in the sky which comes from the Cornish language term for the sun dog lagas awel meaning weather's eye (lagas - eye, awel - weather/wind). This is in turn related to the Anglo-Cornish term cock's eye for a halo round the sun or the moon, also a token of bad weather.