Stars are born in dense clouds of dust and gas that can now be studied in unprecedented detail with Herschel. Although jets and winds of gas have been seen coming from young stars in the past, it has always been a mystery exactly how a star uses these to blow away its surroundings and emerge from its birth cloud.
NGC 1999 sits next to a black patch of sky. For most of the 20th century, such black patches have been known to be dense clouds of dust and gas that block light from passing through.
NGC 1999 is the green tinged cloud towards the top of the image. The dark spot to the right was thought to be a cloud of dense dust and gas until Herschel looked at it. It is in fact a hole that has been blown in the side of NGC 1999 by the jets and winds of gas from the young stellar objects in this region of space.
This image combines Herschel PACS 70 and 160 micron data, and 1.6 and 2.2 micron data with the NEWFIRM camera on the Kitt Peak 4 meter.
(Photo Credit: ESA/HOPS Consortium)
When astronomers looked in its direction to study nearby young stars, the cloud continued to look black. The researchers were surprised because Herschel's infrared eyes are designed to see into such clouds. Either the cloud was immensely dense or something was wrong.
The view from ground-based telescopes revealed the same thing, which lead scientists to believe that this patch looks black because it is truly empty. Something has blown a hole right through the cloud. "No-one has ever seen a hole like this," says Tom Megeath, of the University of Toledo.
The astronomers think that the hole must have been opened when the narrow jets of gas from some of the young stars in the region punctured the sheet of dust and gas that forms NGC 1999. The powerful radiation from a nearby mature star may also have helped to clear the hole. Whatever the precise chain of events, it could be an important glimpse into the way newborn stars disperse their birth clouds.