File:Protostellar jet.jpg

English: This composite image, made with two cameras aboard NASA's Hubble Space Telescope, shows a pair of 12 light-year-long jets of gas blasted into space from a young system of three stars. The jet is seen in visible light, and its dusty disk and stars are seen in infrared light. These stars are located near a huge torus, or donut, of gas and dust from which they formed. This torus is tilted edge-on and can be seen as a dark bar near the bottom of the picture.

Apparently, a gravitational brawl among the stars occurred a few thousand years ago and kicked out one member (on the left edge of the bright blob above the disk). As a result, the two other stars were joined together as a tight binary pair and flew off in the opposite direction, and appear as a red blob below the disk.

The huge jet comes from one of the stars in this tight binary pair. The star spews out streams of gas in opposite directions, like water from a garden hose. It is not a smooth flow, but rather happens episodically, creating lumps of gas that fly across space at over one million miles per hour. These gaseous cannonballs catch up with and "rear-end" slower moving blobs, creating a pattern that resembles a string of Christmas lights embedded in the jet.

The visible-light image was taken with Hubble's Wide Field Planetary Camera 2 in Nov. 1998 and the infrared image by Hubble's Near Infrared Camera and Multi-Object Spectrometer in Mar. 1998. The disk and associated stars are embedded in a large dark cloud and are only visible at infrared wavelengths.