Neptune was observed on the night of May 24th, 1999. Images were
obtained in broad band J and H (blue and red images below,
respectively) and in the methane absorption band at 1.17 microns
in the J band (green). Neptune itself was used as a guide star,
albeit its large diameter (2.3"). Exposure times were 3 x 60
seconds in J band, 3 x 180 seconds in the methane band and 3 x
60 seconds in H band. On the lower right hand side a very
powerful storm in the upper atmosphere is seen travelling from
right to left as time goes on.
These images were combined to create the "true" color image below, but
the very fast rotation of Neptune's upper atmopshere produces
the apparent chromatic shift visible in the images. A next step
in the data reduction will be to de-rotate the images and
combine them with the same longitudinal reference.
Follow this link to see what the same images would have looked like without adaptive optics .