A dark column of dust curls through glowing gas in Cepheus: the Elephant's Trunk Nebula, catalogued as IC 1396A. It is a dense globule on the rim of the much larger emission nebula IC 1396, about 3,000 light-years away. Ultraviolet light and a strong stellar wind from the massive multiple star HD 206267 ionize the hydrogen around it and press the cloud’s edge into a bright, winding rim.
The album is framed on HIP 106890, a hot blue star of spectral type B1.5 that lies only about 12 arcseconds from HD 206267. At magnitude 7.5 it needs a telescope or binoculars, and imagers often use it to center this field. Both stars belong to Trumpler 37, the young cluster at the heart of the nebula.
The trunk is still forming stars. Infrared images show protostars younger than 100,000 years buried in the dust, and a small round cavity near the head holds two young stars whose winds have opened a pocket in the cloud. The column runs for more than 20 light-years. Around it, IC 1396 stretches roughly 150 light-years across the sky.
Facts
- Elephant's Trunk Nebula (IC 1396A), a dust column in the emission nebula IC 1396
- Constellation Cepheus, about 3,000 light-years from Earth
- The trunk is more than 20 light-years long
- IC 1396 is roughly 150 light-years across and covers about 3° of sky
- HIP 106890 is a magnitude-7.5 B1.5 star, about 12″ from the ionizing star HD 206267
- Protostars younger than 100,000 years lie in the trunk, within the cluster Trumpler 37
