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Sky's 'False Suns' Dazzle in Rare Optical Show
25 Jan
Summary
- Sundogs are optical effects caused by ice crystals in cold air.
- They appear as bright spots flanking the sun, bending light by 22 degrees.
- Ancient myths linked these 'companion suns' to mythological dogs.

Residents in Russia's Sakhalin region recently witnessed a striking atmospheric display known as sundogs. These phenomena, characterized by bright spots appearing to the left and right of the sun, are optical effects produced by ice crystals in cold air.
These hexagonal ice crystals, often found at high altitudes or as diamond dust near the ground in extremely cold conditions, refract sunlight. This refraction bends light by a minimum of 22 degrees, causing the sundogs to appear at the same height as the sun. The effect can produce vibrant colors, with reds closest to the sun and blues on the outer edges.
The name "sundog" is believed to stem from ancient mythology, possibly referencing Greek tales of companion figures or dogs accompanying a deity across the sky. The more scientific term, parhelia, literally means "with the sun." Optimal viewing conditions include a low sun angle, such as during sunrise or sunset, and cold temperatures, making higher latitudes in winter prime locations for spotting these shimmering illusions.




