When stars form, within giant clouds of cool molecular hydrogen, some of the surrounding material collapses under gravity and form a rotating flattened disk encircling the newborn star.
Though planets will later congeal in the disk, at this early stage the protostar is feeding on the disk with a huge appetite. Gas from the disk rains down onto the protostar and engorges it. Superheated material spills away and is shot outward from the star in opposite directions.
Shock fronts develop along the jets and heat the surrounding gas to thousands of degrees Fahrenheit. The jets collide with the surrounding gas and dust and clear vast spaces, like a stream of water plowing into a hill of sand. The shock fronts form tangled, knotted clumps of nebulosity and are collectively known as Herbig-Haro [HH] objects. The prominent HH object shown in this image is HH 24.
Overall, just a handful of HH jets have been spotted in this region in visible light, and about the same number in the infrared. Hubble’s observations for this image were performed in infrared light, which enabled the telescope to peer through the gas and dust cocooning the newly forming stars and capture a clear view of the HH objects.
These young stellar jets are ideal targets for NASA’s upcoming James Webb Space Telescope, which will have even greater infrared wavelength vision to see deeper into the dust surrounding newly forming stars.
image credits: nasa/esa
article source: nasa.gov