Some explanations of the Solar Halo which I saw (Photo by me- 12:30 noon-May 7, 2010) : (texts courtesy of Wikipedia)
A halo (ἅλως; also known as a nimbus, icebow or Gloriole) is an optical phenomenon produced by ice crystals creating colored or white arcs and spots in the sky.Light passing through the hexagonal ice prisms is deflected twice, which produces deviation angles ranging from 22° to 50°.
Like other ice halos, 22° halos appear when the sky is covered by thin cirrus clouds containing the ice crystals that cause the phenomenon.