Called NGC 3603, the region lies 20,000 light-years away in the Southern constellation of Carina. Tipped off by the optical studies, they scanned their data for the objects and found them there, unexpectedly bright. Later, they found a fourth object that had not been picked up in the original HST study. Apart from the objects in Orion and NGC 3603, only two other proplyds have been found. There may be many reasons for this apparent scarcity.
Optical telescopes can see proplyds only when they are lying against a brightly lit background.
The green contour lines are an Australia Telescope radio image of the star- forming region NGC 3603. They are overlaid on HST images of the same region. The blobs that may be forming star-systems are marked as P1, P2, P3 and P4. Their tadpole shape is not apparent at this scale but can be seen in close-ups. M cke, B. Koribalski, A.F.J. Moffat, M.F. Corcoran, I.R. Stevens.