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The phenomenon of "Sun Dog" is sometimes also referred to as "Parhelion" which is derived from Greek, because parhelion means a phenomenon when looking at a collection of additional light on both sides or more of the sun of a collection of light named halo. Sometimes, the collection of light looks like a ball that makes us think that the light is an extra sun.
The word "Sun Dog" comes from the phenomenon itself because the extra sun is seen as a dog that sits nicely next to its master, the sun of our earth. The "Sun Dog" mortgage is very rare to meet because it requires a special atmospheric condition that can ultimately emerge an illusion in the sighting eye.
This occurs when there is a large collection of hexagonal ice crystals formed in high and cold cirrus clouds, or during very cold weather. Ice crystals can also mean diamond dust floating in the air at low altitudes. Then the ice crystals act as a horizontally arranged prism in the atmosphere which causes the light to be refracted with a minimum angle of 22˚. This process is similar to the process of creating a rainbow but, the rainbow is formed because the sunlight shines on the water droplets in the sky.
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Natural phenomena such as "Sun Dog" can appear anywhere and anytime as long as the sun shines brightly in the sky. However, it will be easier to see when the sun is in a position lower than the horizon line (sunrise or sunset). As the sun rises until the sun reaches its highest point, "Sun Dog" will begin to shift from a 22˚ angle and eventually disappear. Generally "Sun Dog" is red when it is at the closest distance from the sun. As he moves away from the sun his color will turn blue.
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The phenomenon that always comes along with "Sun Dog" is "Parhelic Circle." Parhelic circle is an optical phenomenon occurring in the sky that appears as a horizontal line or a luminous curved line parallel to the horizon at the same height as the sun. White lines are formed because the line is formed from the reflection of sunlight but, can be blue to greenish when approaching 120˚ parhelia and reddish purple along the outline.
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Although often only seen a piece, but this curved line can form a perfect circle in the sky. Just like "Sun Dog", "Parhelic Circle" is also formed due to sunlight being deflected by hexagonal crystal ice. In "Parhelic Circle" the required hexagonal ice crystals are vertically shaped while, on "Sun Dog" the required hexagonal crystal is horizontal. The reflection of light on the hexagonal ice crystals is the reflection of external light (without any light passing through the crystal) resulting in "Parhelic Circle" close to the sun, or internal (one or more reflections occurring within the crystal) resulting in many circles being formed located far from the sun. Due to the increase in the number of reflections so as to form an asymmetric refraction that forms several colors that are located away from the sun.