APOD: The Elephant's Trunk Nebula in Cepheus (2019 Aug 16)

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APOD Robot
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APOD: The Elephant's Trunk Nebula in Cepheus (2019 Aug 16)

Post by APOD Robot » Fri Aug 16, 2019 4:07 am

Image The Elephant's Trunk Nebula in Cepheus

Explanation: Like an illustration in a galactic Just So Story, the Elephant's Trunk Nebula winds through the emission nebula and young star cluster complex IC 1396, in the high and far off constellation of Cepheus. Also known as vdB 142, the cosmic elephant's trunk is over 20 light-years long. This colorful close-up view was recorded through narrow band filters that transmit the light from ionized hydrogen, sulfur, and oxygen atoms in the region. The resulting composite highlights the bright swept-back ridges that outline pockets of cool interstellar dust and gas. Such embedded, 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. The dramatic scene spans a 1 degree wide field, about the size of 2 Full Moons.

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Re: APOD: The Elephant's Trunk Nebula in Cepheus (2019 Aug 16)

Post by starsurfer » Fri Aug 16, 2019 9:34 am

APOD Robot wrote:
Fri Aug 16, 2019 4:07 am
Also known as vdB 142
Actually vdB142 refers to a small reflection nebula that isn't visible in mapped colour narrowband images. The catalogue designation for the Elephant Trunk Nebula is IC 1396A.

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Re: APOD: The Elephant's Trunk Nebula in Cepheus (2019 Aug 16)

Post by neufer » Fri Aug 16, 2019 11:39 am

starsurfer wrote:
Fri Aug 16, 2019 9:34 am
APOD Robot wrote:
Fri Aug 16, 2019 4:07 am

Also known as vdB 142
Actually vdB142 refers to a small reflection nebula that isn't visible in mapped colour narrowband images. The catalogue designation for the Elephant Trunk Nebula is IC 1396A.
https://apod.nasa.gov/apod/ap011011.html wrote: :arrow: APOD Explanation: A gorgeous collection of dust and gas nebulae in the Northern Milky Way graces the high and far off constellation of Cepheus. With colors based on astronomical filters, this close up of the region highlights stars embedded in curiously shaped cosmic clouds. Near the central faint (9th magnitude) star in the image, dust clouds reflect the starlight, creating a bluish reflection nebula cataloged in 1966 as VDB 142. The area's bright reddish emission nebulae indicate the presence of clouds of atomic hydrogen gas. Stripped of electrons by invisible ultraviolet light, the hydrogen atoms emit their characteristic visible red light as electrons and atoms recombine. Sweptback clouds of obscuring dust, dark nebulae, are silhouetted against the bright background. Representing the stuff stars are made of, all these nebulae lie within the large young star cluster complex IC 1396, 3,000 light years from Earth.

https://www.hansonastronomy.com/vdb142
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orin stepanek
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Re: APOD: The Elephant's Trunk Nebula in Cepheus (2019 Aug 16)

Post by orin stepanek » Fri Aug 16, 2019 12:07 pm

Interesting what we can imagine looking at clouds and nebulae! :wink:
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Smile today; tomorrow's another day!

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Re: APOD: The Elephant's Trunk Nebula in Cepheus (2019 Aug 16)

Post by Guest » Fri Aug 16, 2019 6:17 pm

Hmm, don't the stars in this image have the "raccoon eye" effect from sharpening?

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Re: APOD: The Elephant's Trunk Nebula in Cepheus (2019 Aug 16)

Post by Guest » Fri Aug 16, 2019 6:22 pm

What is the APOD selection criteria? Seems like there are a lot of good images of this subject out there... Chuck has some great images on his Astrobin page, but today's APOD isn't his best work, IMHO.

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Re: APOD: The Elephant's Trunk Nebula in Cepheus (2019 Aug 16)

Post by DrReneigh » Fri Aug 16, 2019 7:09 pm

Hello, This is my first time posting. I apologize if this question has been asked and answered before. Why are beautiful images like the elephant trunk nebula ALWAYS shaped the same-I mean, if they are made out of gases, why don't they eventually change shape and are maybe no longer an elephant trunk? I suspect it has to do with 1) the sheer size of the object-minor changes in the gasses won't be noticeable in something so huge, or 2) the distance/time it takes for us to see the image-what is 50 or 100 years of seeing an image compared to the 3,000 light years distance between us?
Thanks for your time to answer my question!
Renee

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Re: APOD: The Elephant's Trunk Nebula in Cepheus (2019 Aug 16)

Post by BDanielMayfield » Sun Aug 18, 2019 1:06 am

DrReneigh wrote:
Fri Aug 16, 2019 7:09 pm
Hello, This is my first time posting. I apologize if this question has been asked and answered before. Why are beautiful images like the elephant trunk nebula ALWAYS shaped the same-I mean, if they are made out of gases, why don't they eventually change shape and are maybe no longer an elephant trunk? I suspect it has to do with 1) the sheer size of the object-minor changes in the gasses won't be noticeable in something so huge, or 2) the distance/time it takes for us to see the image-what is 50 or 100 years of seeing an image compared to the 3,000 light years distance between us?
Thanks for your time to answer my question!
Renee
Your first suspicion is correct, but your second is not. The delay in seeing events due to distance and the speed of light has nothing to do with the rate at which they occur.
Just as zero is not equal to infinity, everything coming from nothing is illogical.

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Re: APOD: The Elephant's Trunk Nebula in Cepheus (2019 Aug 16)

Post by DrReneigh » Mon Aug 19, 2019 4:12 pm

BDanielMayfield wrote:
Sun Aug 18, 2019 1:06 am
DrReneigh wrote:
Fri Aug 16, 2019 7:09 pm
Hello, This is my first time posting. I apologize if this question has been asked and answered before. Why are beautiful images like the elephant trunk nebula ALWAYS shaped the same-I mean, if they are made out of gases, why don't they eventually change shape and are maybe no longer an elephant trunk? I suspect it has to do with 1) the sheer size of the object-minor changes in the gasses won't be noticeable in something so huge, or 2) the distance/time it takes for us to see the image-what is 50 or 100 years of seeing an image compared to the 3,000 light years distance between us?
Thanks for your time to answer my question!
Renee
Your first suspicion is correct, but your second is not. The delay in seeing events due to distance and the speed of light has nothing to do with the rate at which they occur.
Thanks!