New Jupiter moon S/1999 J1

This photo shows the moving, point-like image of the newly discovered Jupiter moon, S/1999 J 1 , as observed with VLT ANTU and the FORS-1 instrument, low in the sky and just before sunrise on July 28, 2000. It is a composite of three CCD frames, obtained through a R(ed) optical filter. Because of the motion between the exposures, there are three images of the object near each other. Each exposure lasted 1 min. The image quality was 0.7 arcsec, just above the horizon. The field shown in the photo is about 1.5 x 1.5 arcmin 2 ; North is up and East is left.