|  | 
 
         
          |  |  | Corona 
            around the sun. 
 The central blindingly bright disk fringed with red is the aureole. 
            Two rings surround it. The rings in this corona are slightly off centre 
            because of a gradation in droplets sizes in the cloud.
 
 Imaged by Richard Fleet (Glows, 
            Bows & Haloes) in Wiltshire, England during the summer 
            of 2003.
 
 Image © Richard Fleet, shown with permission.
 
 
 
 
 
 
 |  |  
         
          | A corona may be seen when thin clouds partially veil the sun or moon. 
            Look for one around the moon when it is near to full and the sky is 
            dark. When searching for a solar corona, shield 
            the sun and reduce the light intensity to safer levels by looking 
            at the sky reflected in a pool of water 
            or a mirror of plain glass. Staring directly at or near to the sun 
            can permanently damage eyesight. Tips on eye care.
 
 Coronae have an intensely bright central aureole which is almost 
            white and fringed with yellows and reds. Sometimes that is all to 
            be seen but the better coronas have one or more successively fainter 
            and gently coloured soft rings surrounding the aureole. The first 
            ring is bluish on the inside grading through greens and yellows to 
            red outermost. The colours are subtle mixtures rather than the more 
            direct hues of the rainbow. The corona can be 15º or so in diameter 
            and often it shrinks and swells as different clouds scud across the 
            moon.
 
 
 
               
                |  | The coronae is much 
                  smaller than the 22° 
                  halo which can also ring the sun and moon. The corona 
                  also has nothing to do with the Sun's outer atmosphere visible 
                  during a total eclipse and confusingly given the same name. 
 Coronae are produced by the diffraction 
                  of light by tiny cloud droplets or sometimes small ice crystals.
 |  
 |  
 
 
 
 
 |  |