Images captured that the sun was surrounded by concentric rainbow circles.
Hai Phong City and Hai Duong Province were the best places to see sharp images of the rare phenomenon.
According to scientists, this is a normal natural phenomenon, called a solar halo.
A halo is a ring of light that forms around the sun or moon as the sun or moon light refracts off ice crystals present in a thin veil of cirrus clouds.
Head of the Hanoi Astronomy Club Vu The Hoang indicated that this is a normal natural phenomenon which ever appeared in many locations.
Recently, this phenomenon appeared in Lang Son Province and Dong Nai Province on April 18 and May 20.
Images captured that the sun was surrounded by concentric rainbow circles in various places.
