APOD: The Elephant's Trunk in Cepheus (2024 Nov 21)

[APOD Robot]

The Elephant's Trunk in Cepheus

Explanation: Like an illustration in a galactic Just So Story, the Elephant's Trunk Nebula winds through the emission region and young star cluster complex IC 1396, in the high and far off constellation of Cepheus. Also known as vdB 142, this cosmic elephant's trunk is over 20 light-years long. The detailed telescopic view features the bright swept-back ridges and pockets of cool interstellar dust and gas that abound in the region. But the dark, tendril-shaped clouds contain the raw material for star formation and hide protostars within. Nearly 3,000 light-years distant, the relatively faint IC 1396 complex covers a large region on the sky, spanning over 5 degrees. This rendition spans a 1 degree wide field of view though, about the angular size of 2 full moons.

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[Ann]

Well, in the Just So story, the Baby Elephant got his trunk when the crocodile pulled on his nose, but the Elephant's Trunk Nebula got its trunk because the stellar wind and torrent of ultraviolet photons from a hot O-type binary star are bearing down on it!

On the Earth, winds are blowing 'sideways', but in nebulas, winds are bearing straight down on hapless 'trunks'! Credit: Azmeyart.

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Just so? Maybe not so. Credit: Rudyard Kipling.

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When everything else has been blown away by the terrifying power of the O-type star, the trunk - that is, the pillar - is the last man standing!

It's hot in here! I'm the last man standing. Credit: Ray Majoran

Last man standing. Credit: Bernard Herrera.

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What makes the Elephant Trunk unusual compared with most other cosmic pillars is that we can clearly see that stars are being born inside the pillar's "head". They are born in there because the gas at the top of the Elephant's Trunk is being compressed by the stellar wind and ultraviolet light from the O-type star, and as gas gets denser, stars can be born from it.

Small stars are peeking out from inside the cavity in the Elephant's Trunk Nebula at upper left. Credit: KPNO/NOIRLab/NSF/AURA/Jeff Hapeman/Adam Block

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Let's admire Alan Dyer's portrait of IC 1396, where the Elephant's Trunk Nebula is located:

IC 1396, with giant and very cool red giant Mu Cephei at upper left.
Where is the Elephant's Trunk Nebula? Oh, it's immediately to the right
of hot central O-type star HD 206267! Credit: Alan Dyer.

So where in the sky is the Elephant's Trunk Nebula located? After all, it's good to know your neighbors!

It's good to know your neighbors!

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IC 1396, home of the Elephant's Trunk Nebula in Cepheus, is located north of the North America Nebula in Cygnus. Credit: Pere Sanz.

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Ann