Cometary globules are interstellar clouds with comet-like morphology, consisting of compact dusty "heads" and long, faintly luminous "tails". While they were first observed mostly in the outskirts of the Gum nebula, they have been found later to be common among interstellar clouds, with scales ranging from isolated tiny globules to complete cometary shaped star-forming regions such as the Corona Australis cloud. It is thought that the formation of these objects is caused by either radiation-driven implosion of an isolated globule or a supernova blast wave colliding with an extended globule.
CG1 (upper left in the image) and CG2 (lower right in the image) are “classic” cometary globules in the Gum Nebula and the first two to be listed. Located about 1000 light years away from Earth, they tails have an apparent lenght as the full Moon and point away from the centre of the Gum Nebula. Recent studies found evidence of star formation in both these cometary globules, with a large predominance in CG1.
Takahashi CCA250 (250/f5) - ZWO 6200MM Ha (360m) L (510m) R (90m) G (110m) B (90m) - AMT Observatory (
A.Lau/M.Lorenzi/T.Tse), Río Hurtado, Chile.
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