HH 288 - The Dragon Jet


This is an image of HH288, also known as the Dragon Jet, in Cassiopeia. The Dragon name (due to Sande McCaughrean) comes from the similarity to a Chinese dragon, with the fire-breathing head to the lower-left (south-east), and the long tail to the upper-right (north-west).

HH288 is a newly discovered infrared jet, driven by a very young proto-stellar source sitting more or less in the middle of the picture. A massive bipolar outflow is being driven from the recently formed source at velocities of a few hundred kilometres per second. Where the bipolar jet hits the ambient medium, gas is shocked, resulting in the emission seen here. The total extent of the jet is over 1 parsec, making this the largest known infrared (i.e. young) jet.

The image was taken through a 1% narrow-band filter centred at 2.122 microns, admitting the v=1-0 S(1) line of molecular hydrogen. The total integration time is 33 minutes; the seeing 0.8 arcsec FWHM; the pixel size 0.4 arcsec; the field-of-view is 256 by 312 arcsec.

The data were taken on June 5th 1996 by Mark McCaughrean.