what causes a double rainbow
Secondary rainbows are caused by a double reflection of sunlight inside the raindrops, and are centered on the sun itself. They are about 127Â° (violet) to 130Â° (red) wide. Since this is more than 90Â°, they are seen on the same side of the sky as the primary rainbow, about 10Â° above it at apparent angles of 50â53Â°.