Observer: European Southern Observatory
Location: European Southern Observatory, La Silla, Chile
Date: June 18, 1999
False-colour composite photo of Comet Hale-Bopp, obtained on June 18, 1999, with the SUSI2 instrument at the ESO 3.5-m New Technology Telescope (NTT) at La Silla. Three exposures were made through V- (green-yellow; 60 sec; here colour-coded as "blue"), R- (red; 30 sec; "green") and I (infrared, 30s; "red"), respectively. The sky field measures about 7.2 x 7.2 arcmin2 (2048x2048 pixels). The pixel size is 0.21/arcsec. North is up and East is left. The comet moved just over 1 arcsec during this series of exposures. The bright star in the lower left quadrant is unsually red. The broad line extending to the right from this star is an optical reflection in the telescope. A distant galaxy is seen to the right below the centre (at 4 o'clock) of the comet.
This photo is a "sum" of the three exposures that served as the basis for the colour image. It has been contrast-enhanced to show the truly enormous size of the comet's coma, over 3 arcmin across. The optical reflection from the bright star to the lower left was also enhanced by this process.