Homunculus Nebula

emission nebula
name = Homunculus Nebula


epoch = J2000
type = Emission nebula
ra = RA|10|45|03.6
dec = DEC|-59|41|04
dist_ly = 7,500 ly
z =
appmag_v=6.21 (-0.8–7.9)
size_v =
constellation = Carina
radius_ly =
absmag_v =
notes = Bipolar nebula
names =

The Homunculus Nebula is an emission nebula surrounding the massive star Eta Carinae. The nebula is embedded within a much larger H II region, the Eta Carinae Nebula.

The Homunculus (which is from the Latin meaning "Little Man") is believed to have been ejected in an enormous outburst which Eta Carinae underwent, the light of which first reached Earth in 1841. Following this outburst, Eta Carinae became the second-brightest star in the sky after Sirius, but since this time, the gas and dust it ejected has obscured much of its light. The explosion produced two polar lobes and a large thin equatorial disk, all moving outward at about 1.5 million miles per hour. Future eruptions are still a possibility.

Even though Eta Carinae is about 7,500 light-years away, structures only 10 billion miles across (about the diameter of our solar system) can be distinguished. Dust lanes, tiny condensations, and strange radial streaks all appear with unprecedented clarity. The outer ejecta blobs are 100,000 times fainter than the brilliant central star. Excess violet light escapes along the equatorial plane between the bipolar lobes. Apparently there is relatively little dusty debris between the lobes down by the star; most of the blue light is able to escape. The lobes, on the other hand, contain large amounts of dust which preferentially absorb blue light, causing the lobes to appear reddish.