May 17, 2005
False-colour, infrared composite photo of the dark cloud Barnard 68 , obtained on March 8-9, 1999, with the SOFI instrument at the ESO 3.5-m New Technology Telescope (NTT) at La Silla. Three exposures were made through J- (wavelength 1.25 Âµm - 3 min; here colour-coded as "blue"), H- (1.65 Âµm - 30 min; "green") and Ks-filters (2.16 Âµm - 30 min; "red"), respectively. The "reddening" of the background stars that are seen through the cloud is very obvious. It is due to the larger obscuration in shorter wavebands. The sky field measures about 4.9 x 4.9 arcmin2 (1024x1024 pixels). A slight mismatch between the individual frames is present in the upper corners; this is caused by atmospheric effects. The pixel size is 0.29/arcsec. North is up and East is left.
Topics: Technology Internet, Barnard 68, Dark nebulae, Telescopes, Ophiuchus constellation, Filter, Infrared, New Technology Telescope, La Silla Observatory, European Southern Observatory