A video of a rare celestial phenomenon showing three suns together in the sky has stunned the people of China. On November 28, the footage, captured in Hulunbuir, Inner Mongolia, showed the sun in the centre and two other small coloured patches or phantom suns on the left and the right side of it.
According to scientists, this phenomenon is known as 'sundog'. They say that such a phenomenon takes place when the temperature reduces below minus 30 degree Celsius and the sun interacts with vapour and ice crystals.
A resident, who filmed the clip of the rare incident, posted the video on social media and captioned it as: "Look, there are three suns in the background."
Peer Video reported that the residents of Hulunbuir have seen the incident happen twice in a day and the first occurrence recorded in the morning lasted for around two hours.
Daily Mail quoted Zhao Kexin, who works at the Hulunbuir Meteorological Station, as saying that "sun dog" often occurs in the region during winter season.
Sundogs, which are also known as mock suns, are generally visible when sunlight shines through ice crystals in the air. Live Science explains that sundogs are formed "from hexagonal ice crystals in high and cold cirrus clouds or, during very cold weather. These ice crystals act like prisms, bending the light rays passing through them."
"As the crystals sink through the air they become vertically aligned, refracting the sunlight horizontally so that sundogs are observed," Live Science said.
This phenomenon is mostly seen in the months of January, April, August and October when the "sun is lower on the horizon".
Greek and Roman authors have also mentioned about such phenomenon in ancient days. "Two mock suns rose with the sun and followed it all through the day until sunset," Greek philosopher Aristotle (384 B.C. – 322 B.C.) noted.