Sun dog

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.[17]

The poet Aratus (Phaenomena, lines 880–891) mentions parhelia as part of his catalogue of Weather Signs; according to him, they can indicate rain, wind, or an approaching storm.[18]

Artemidorus in his Oneirocritica ('On the Interpretation of Dreams') included the mock suns amongst a list of celestial deities.[19]

A passage in Cicero's On the Republic (54–51 BC) is one of many Roman authors who refer to sun dogs and similar phenomena:

Be it so, said Tubero; and since you invite me to discussion, and present the opportunity, let us first examine, before any one else arrives, what can be the nature of the parhelion, or double sun, which was mentioned in the senate. Those that affirm they witnessed this prodigy are neither few nor unworthy of credit, so that there is more reason for investigation than incredulity.[20]

Seneca makes an incidental reference to sun dogs in the first book of his Naturales Quaestiones.[21]

The 2nd-century Roman writer and philosopher Apuleius in his Apologia says "What is the cause of the prismatic colours of the rainbow, or of the appearance in heaven of two rival images of the sun, with sundry other phenomena treated in a monumental volume by Archimedes of Syracuse."[22]

Fulcher of Chartres, writing in Jerusalem in the early twelfth century, notes in his Historia Hierosolymitana (1127) that on February 23, 1106

... from the third hour (9 am) until midday, we saw left and right from the Sun what looked like two other Suns: they did not shine like the big one, but smaller in appearance and radiance they reddened moderately. Above their circle a halo appeared, shining very brightly, extending in its breadth as if it were some kind of city. Inside this circle a half-circle appeared, similar to a rainbow, distinct in its fourfold color, in the higher part curved towards the two aforementioned Suns, touching them in an embrace of the Sun. [23]

The prelude to the Battle of Mortimer's Cross in Herefordshire, England in 1461 is supposed to have involved the appearance of a halo display with three "suns". The Yorkist commander, later Edward IV of England, convinced his initially frightened troops that it represented the three sons of the Duke of York, and Edward's troops won a decisive victory. The event was dramatized by William Shakespeare in King Henry VI, Part 3,[24] and by Sharon Kay Penman in The Sunne In Splendour.

Another early clear description of sun dogs is by Jacob Hutter, who wrote in his Brotherly Faithfulness: Epistles from a Time of Persecution:

My beloved children, I want to tell you that on the day after the departure of our brothers Kuntz and Michel, on a Friday, we saw three suns in the sky for a good long time, about an hour, as well as two rainbows. These had their backs turned toward each other, almost touching in the middle, and their ends pointed away from each other. And this I, Jakob, saw with my own eyes, and many brothers and sisters saw it with me. After a while the two suns and rainbows disappeared, and only the one sun remained. Even though the other two suns were not as bright as the one, they were clearly visible. I feel this was no small miracle…[25]

The observation most likely occurred in Auspitz (Hustopeče), Moravia on 31 October 1533. The original was written in German and is from a letter originally sent in November 1533 from Auspitz in Moravia to the Adige Valley in South Tyrol. The Kuntz Maurer and Michel Schuster mentioned in the letter left Hutter on the Thursday after the feast day of Simon and Jude, which is 28 October. The Thursday after was 30 October.[26] It is likely that the "two rainbows with their backs turned toward each other, almost touching" involved two further halo phenomena, possibly a circumzenithal arc (prone to co-occur with sun dogs) together with a partial 46° halo or supralateral arc.[27]

The so-called "Sun Dog Painting" (Vädersolstavlan) depicting Stockholm in 1535 and the celestial phenomenon at the time interpreted as an ominous presage

While mostly known and often quoted for being the oldest color depiction of the city of Stockholm, Vädersolstavlan (Swedish; "The Sundog Painting", literally "The Weather Sun Painting") is arguably also one of the oldest known depictions of a halo display, including a pair of sun dogs. For two hours in the morning of 20 April 1535, the skies over the city were filled with white circles and arcs crossing the sky, while additional suns (i.e., sun dogs) appeared around the sun. The phenomenon quickly resulted in rumours of an omen of God's forthcoming revenge on King Gustav Vasa (1496–1560) for having introduced Protestantism during the 1520s and for being heavy-handed with his enemies allied with the Danish king.

Hoping to end speculations, the Chancellor and Lutheran scholar Olaus Petri (1493–1552) ordered a painting to be produced documenting the event. When confronted with the painting, the king, however, interpreted it as a conspiracy – the real sun of course being himself threatened by competing fake suns, one being Olaus Petri and the other the clergyman and scholar Laurentius Andreae (1470–1552), both thus accused of treachery, but eventually escaping capital punishment. The original painting is lost, but a copy from the 1630s survives and can still be seen in the church Storkyrkan in central Stockholm.

A series of complex parhelia displays in Rome in 1629, and again in 1630, were described by Christoph Scheiner in his book Parhelia, one of the earliest works on the subject. It had a profound effect, causing René Descartes to interrupt his metaphysical studies and led to his work of natural philosophy called The World.[28]

On 20 February 1661 the people of Gdańsk witnessed a complex halo display, described by Georg Fehlau in a pamphlet, the Sevenfold Sun Miracle, and again the following year by Johannes Hevelius in his book, Mercurius in Sole visus Gedani.

On 18 June 1790 Johann Tobias Lowitz, in Saint Petersburg, Russia, observed a complex display of haloes and parhelia which included his Lowitz arcs.

In 1843, winter in the British Colony of Newfoundland was referred to as the 'Winter of Three Suns' and was unusually cold with 15 days of temperatures between 3–10 degrees below zero.[29]

"Part of the time we marched in the teeth of a biting storm of snow, and at every hour of the day the sun could be discerned sulking behind soft grey mists in company with rivals, known in the language of the plains as 'Sun-dogs', whose parahelic splendors warned the traveler of the approach of the ever-to-be-dreaded 'blizzard'."[30]

On 14 February 2020, the people of Inner Mongolia Autonomous Region witnessed a complex halo display, in which all five sun halos were linked to each other by rays, forming a circle among them.[31]