Close-up Views of a Stellar Jet

These images taken by NASA's Hubble Space Telescope show how a bright, clumpy jet ejected from a young star has changed over time.

The jet, called Herbig-Haro 34 (or HH 34), is a signpost of star birth. Several bright regions in the lumpy gas signify where material is slamming into each other, heating up, and glowing. The images show that a couple of bright areas on the right faded over time, as heated material cooled (shown in red). Two regions at left, however, brightened over the 14-year span of observations, pinpointing fresh collision sites. The blue fan-shaped feature at left outlines the edge of the outflow cavity, illuminated by the fledgling star. A small knot of material within the blue feature is either a new jet or magnetic energy being emitted by the star.

Ejected episodically by a young star like salvos from a cannon, the blobby material in HH 34 zips along at more than 440,000 miles (700,000 kilometers) an hour. When launched, the speedy jet may initially be confined to a narrow beam by the star's powerful magnetic field.

These images are part of a series of time-lapse movies astronomers have made showing the motion of several Herbig-Haro jets over time. The movies were stitched together from images taken over a 14-year period by Hubble's Wide Field Planetary Camera 2. Hubble followed the HH 34 jets over three epochs: 1994, 1998, and 2007.

HH 34 is roughly 1,350 light-years from Earth, near the Orion Nebula.

About the colours

This image is a composite of separate exposures acquired by the WFPC2 instrument on HST. The color results from assigning different hues (colors) to each monochromatic (grayscale) image associated with an individual filter. In this case, the assigned colors are: Cyan: F656N (H-alpha) Orange: F673N ([S II])

About the data

The observations of HH 34 are taken from HST proposals: 5114 J. Westphal (Caltech), 5504 and 6794 : B. Reipurth (University of Hawaii), and 11179 : P. Haritgan (Rice University).