Thursday, April 22, 2021

The Elephant’s Trunk Nebula

The Elephant’s Trunk Nebula is a dark and dense gaseous/dusty globule, located at a distance of around 2,400 light years in the constellation of Cepheus.

The small structure that is also known as IC 1396A, is part of IC 1396, a large emission line nebula.

It is powered by HD 206267, a O6V((f)) + O9V triple star, that is composed from a binary system with a period of 3.7 days, and a third component that is further away. The star is responsible for powering the whole nebula and not only the Elephant’s Trunk.

At the “head” of the nebula there are two older stars. The latter, together with the massive stars within IC 3196, are responsible for the condensation of the Elephant’s Trunk. This has made the region a site of star formation, where several young stars have been identified through infrared observations.

Image 1: Composite optical image of the Elephant’s Trunk Nebula. The image was created using narrow band filters that are focused on the emission of ionized oxygen ([O III], blue), ionized hydrogen (Hα, green), and ionized sulfur ([S II], red).


Image 2: Composite infrared image of the Elephant’s Trunk Nebula taken with the Spitzer Space Telescope. The image was created using broadband filters that are centred at 3.6 microns (blue), 4.5 microns (green), 5.8 microns (orange) and 8.0 microns (red). At the head of the nebula, two stars known as LkHa 349 and LkHa 349c have formed a cavity. The two stars appear to have the same brightness in this infrared image, but this is not the case when they are compared at optical bands. This is most likely due to a thick dust disk around LkHa 349c

Image 1 Credit: Chuck Ayoub

Image 2 Credit: NASA/JPL-Caltech/W. Reach (SSC/Caltech)

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