For the first time in my life I was able to witness this wonderful phenomenon live. It appeared on 26.02.2018 over southern Brazil, Florianópolis.
A Solar Halo is an optical phenomenon produced by light interacting with ice crystals suspended in the atmosphere, resulting in a wide variety of colored or white rings, arcs and spots in the sky. The most common halo is the 22° halo, a series of coloured arcs, or in some cases complete circles, of 22° angular radius with the Sun or Moon at its centre.
The ice crystals responsible for halos are typically suspended in cirrus or cirrostratus clouds high (5–10 km, or 3–6 miles) in the upper troposphere. In this case it is called a Double Solar Halo. A circle near the sun and another circle seems to be a rainbow that you can see below.
