They were combined into a colour photo, cf. The VLT photo shows it as a compact, opaque and rather sharply defined object, the central parts of which are so dense that they completely block out the light from the stars behind. It is known that clouds like B68 at some moment begin to contract and subsequently transform themselves into normal, hydrogen-burning stars. For the first time, it has been possible to look right through even the most opaque regions of such an object and learn what is inside in unsurpassed detail. It is due to the larger obscuration in shorter wavebands.
North is up and East is left.
The measured seeing was about 0.6 arcsec during several hours while these exposures were being made. They were then added to produce three frames that form the basis for the subsequent study and which were used to produce the images shown here. It is evident that the obscuration caused by the cloud diminishes dramatically with increasing wavelength. Since the outer regions of the cloud are less dense than the inner ones, the apparent size of the cloud also decreases, as more background stars shine through the outer parts. Each frame covers an area of 4.9 x 4.9 arcmin 2 .