APOD: Cygnus: Bubble and Crescent (2023 Sep 04)

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APOD: Cygnus: Bubble and Crescent (2023 Sep 04)

Post by APOD Robot » Mon Sep 04, 2023 4:07 am

Image Cygnus: Bubble and Crescent

Explanation: As stars die, they create clouds. Two stellar death clouds of gas and dust can be found toward the high-flying constellation of the Swan (Cygnus) as they drift through rich star fields in the plane of our Milky Way Galaxy. Caught here within the telescopic field of view are the Soap Bubble (lower left) and the Crescent Nebula (upper right). Both were formed at the final phase in the life of a star. Also known as NGC 6888, the Crescent Nebula was shaped as its bright, central massive Wolf-Rayet star, WR 136, shed its outer envelope in a strong stellar wind. Burning through fuel at a prodigious rate, WR 136 is near the end of a short life that should finish in a spectacular supernova explosion. Discovered in 2013, the Soap Bubble Nebula is likely a planetary nebula, the final shroud of a lower mass, long-lived, Sun-like star destined to become a slowly cooling white dwarf. Both stellar nebulas are about 5,000 light-years distant, with the larger Crescent Nebula spanning about 25 light-years across. Within a few million years, both will likely have dispersed.

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Re: APOD: Cygnus: Bubble and Crescent (2023 Sep 04)

Post by emc » Mon Sep 04, 2023 4:45 am

Beautiful colors! How’d they do that?
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Re: APOD: Cygnus: Bubble and Crescent (2023 Sep 04)

Post by MelvzLuster » Mon Sep 04, 2023 8:10 am

Great & marvelous, a lifecycle of stars begins with dust formation and ends with a supernova explosion creating dust again.
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Re: APOD: Cygnus: Bubble and Crescent (2023 Sep 04)

Post by Ann » Mon Sep 04, 2023 8:51 am

emc wrote: Mon Sep 04, 2023 4:45 am Beautiful colors! How’d they do that?
Well, sigh. I guess I'm the one who should say something about it, as I am the self-appointed Color Commentator of Starship Asterisk*. Problem is, I'm not too interested in dying or dead stars. In fact, I find them somewhat depressing.

Of course I realize that on the grand scale of things, stars die, and accepting that is accepting the laws of the Universe. But the grand scale of things is one thing, and looking at an individual dead or dying star is something else.

(To make a morbid comparison here, imagine if no human being who was ever born had ever died. The very thought of it boggles the mind, and it helps you accept that, yes, people die, and we have to die, because otherwise life on Earth would be impossible. But that realization doesn't mean you have to take "a happy and positive interest" in individual people belonging to the same time frame as yourself transitioning from the living to the dead state. Although I admit it was interesting to see the possibly accidentally mummified 17th century bishop that was found in a wall in the cathedral of Lund, Sweden.)


Anyway. The colors of this APOD. I was looking for technical information on this image, but the only info I could find was in Arabic, so that wasn't helpful to me. But a good way to figure out how a picture may have been produced is to compare it with other pictures of the same object(s), where technical information is available.

Crescent and Bubble Nebula Iván Éder.png
Crescent and Bubble Nebula. Image Credit: Iván Éder

We can tell at a glance that Abdullah Al-Harbi's image is "bluer" than Iván Éder's. As for the technical information on Iván Éder's image, it is here. We are told that Iván Éder used an Ha (hydrogen alpha) and an OIII filter for his image, plus "unfiltered DSLR images" (whatever that means).

So Iván Éder photographed the Crescent and Bubble Nebula through a narrowband hydrogen alpha filter of this color, ███, and a narrowband OIII filter of this color, ███, and then, in final production, the OIII channel was mapped to a blue color, possibly something like this: ███.


So I think we can say that what looks blue in the portrait of the Crescent Nebula in both the APOD of today and in Iván Éder's image is doubly ionized oxygen, or OIII. This emission is typically found near highly energetic stars, such as Wolf-Rayet stars and the central stars of planetary nebulas. But OIII is normally only found in extremely rarefied conditions, because the emission of OIII can be hindered by the presence of too many other ions, atoms or molecules, or at least that is how I understand it.

We can see that Abdullah Al-Harbi has processed his image in such a way as to emphasize the OIII emission of the two nebulas. The little Bubble Nebula is not rich in OIII, but it does contain some OIII, and enhancing the OIII channel makes the Bubble Nebula stand out against the background. Because the background contains no appreciable OIII at all. That makes the Bubble Nebula definitely easier to spot in Abdullah Al-Harbi's image than in Iván Éder's.

As for the background, it looks "natural" to me in both images. The star colors look normal. So both photographers have used more data for their final images than can be gleaned from just Ha and OIII filter images.

Ann
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Re: APOD: Cygnus: Bubble and Crescent (2023 Sep 04)

Post by alex555 » Mon Sep 04, 2023 9:23 am

The star responsible for Crescent Nebula seems to be the bright point roughly in the middle but on the other hand for Bubble, we cannot clearly see the star which is the cause.

Alex

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Re: APOD: Cygnus: Bubble and Crescent (2023 Sep 04)

Post by TareqPhoto » Mon Sep 04, 2023 9:39 am

I am Arabic and i know some of the details, at least i know the equipment he was using, and in Arabic i can translate because it is my mother language anyway.

I don't post here but i am happy to see an Arabic person to win APOD, i hope one day i can win if i start imaging and keep improving.

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Re: APOD: Cygnus: Bubble and Crescent (2023 Sep 04)

Post by emc » Mon Sep 04, 2023 10:49 am

Ann wrote: Mon Sep 04, 2023 8:51 am
emc wrote: Mon Sep 04, 2023 4:45 am Beautiful colors! How’d they do that?
Well, sigh. I guess I'm the one who should say something about it, as I am the self-appointed Color Commentator of Starship Asterisk*. Problem is, I'm not too interested in dying or dead stars. In fact, I find them somewhat depressing.

Ann
Yes. I’ve only been back here in SA for a week and YOU are the Color Commentator! I was hoping you would be available to answer. I feel we are better friends now. I had three reasons for joining this forum… 1) Make friends 2) learn some stuff and share the joy of outer space 3) therapy for my bipolarness

Thank you for your kind and interesting reply. And I hope you don’t mind me calling you my friend. I had appointed you as a friend a long time ago.
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Re: APOD: Cygnus: Bubble and Crescent (2023 Sep 04)

Post by AVAO » Mon Sep 04, 2023 3:52 pm

alex555 wrote: Mon Sep 04, 2023 9:23 am The star responsible for Crescent Nebula seems to be the bright point roughly in the middle but on the other hand for Bubble, we cannot clearly see the star which is the cause.

Alex

The blue star in the center is a White Dwarf candidate. :brr:

PanSTARRS DR1 PN G075.5+01.7 jac berne (flickr)

alex555

Re: APOD: Cygnus: Bubble and Crescent (2023 Sep 04)

Post by alex555 » Mon Sep 04, 2023 3:55 pm

Thanks ! That star is merely is difficult to guess in the APOD picture !

Alex

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Re: APOD: Cygnus: Bubble and Crescent (2023 Sep 04)

Post by orin stepanek » Mon Sep 04, 2023 6:25 pm

CrescentBubble_AlHarbi_1080.jpg
Bubble nebula always amaze me! 8-)
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Another kitty today! :D
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Re: APOD: Cygnus: Bubble and Crescent (2023 Sep 04)

Post by johnnydeep » Mon Sep 04, 2023 8:47 pm

APOD Robot wrote: Mon Sep 04, 2023 4:07 am Image Cygnus: Bubble and Crescent

Explanation: As stars die, they create clouds. Two stellar death clouds of gas and dust can be found toward the high-flying constellation of the Swan (Cygnus) as they drift through rich star fields in the plane of our Milky Way Galaxy. Caught here within the telescopic field of view are the Soap Bubble (lower left) and the Crescent Nebula (upper right). Both were formed at the final phase in the life of a star. Also known as NGC 6888, the Crescent Nebula was shaped as its bright, central massive Wolf-Rayet star, WR 136, shed its outer envelope in a strong stellar wind. Burning through fuel at a prodigious rate, WR 136 is near the end of a short life that should finish in a spectacular supernova explosion. Discovered in 2013, the Soap Bubble Nebula is likely a planetary nebula, the final shroud of a lower mass, long-lived, Sun-like star destined to become a slowly cooling white dwarf. Both stellar nebulas are about 5,000 light-years distant, with the larger Crescent Nebula spanning about 25 light-years across. Within a few million years, both will likely have dispersed.
So the Soap Bubble Nebula was not discovered in 2013, as the Discovered in 2013 link text says, but in 2008, as the Bubble Nebula link content says:
In fact, amateur astronomer Dave Jurasevich identified it as a nebula on 2008 July 6
And this is confirmed by the Discovered in 2013 link content as well. But it was given an official designation in 2013 as that link says:
LATEST NEWS: On July 26, 2013 the Centre de Donnees Astronomiques de Strasbourg (CDS), the
world referenece database for the identification of astronomical objects and host to the SIMBAD
on-line database, officially designated PN G75.5+1.7 as Ju1 (Jurasevich 1).
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Re: APOD: Cygnus: Bubble and Crescent (2023 Sep 04)

Post by Roy » Mon Sep 04, 2023 9:39 pm

If the distances and diameters given are accurate, the WR136 bubble has expanded to encompass about 8200 cubic light years, and the JU1 bubble 127 cucbic light years. Should we be able to see changes to stars which are now inside the bubbles?

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Re: APOD: Cygnus: Bubble and Crescent (2023 Sep 04)

Post by Chris Peterson » Mon Sep 04, 2023 9:47 pm

Roy wrote: Mon Sep 04, 2023 9:39 pm If the distances and diameters given are accurate, the WR136 bubble has expanded to encompass about 8200 cubic light years, and the JU1 bubble 127 cucbic light years. Should we be able to see changes to stars which are now inside the bubbles?
Even the expanding edge of these objects are hard vacuums. They have no effect at all on stars inside them. Anybody living on planets inside would require high technology to even know those bubbles were there.
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Re: APOD: Cygnus: Bubble and Crescent (2023 Sep 04)

Post by Ann » Tue Sep 05, 2023 2:54 am

AVAO wrote: Mon Sep 04, 2023 3:52 pm
alex555 wrote: Mon Sep 04, 2023 9:23 am The star responsible for Crescent Nebula seems to be the bright point roughly in the middle but on the other hand for Bubble, we cannot clearly see the star which is the cause.

Alex

The blue star in the center is a White Dwarf candidate. :brr:

PanSTARRS DR1 PN G075.5+01.7 jac berne (flickr)
Thanks a bunch for identifying it for us, AVAO (or should I say Jac?)! Indeed, unless the the central star of a planetary nebula is very dust-reddened, it should always be identifyable by its striking blue color - which, of course, represents extremely hot temperatures, not biting cold!!!

It's a great picture, like all the pictures you post here. You created it yourself? Where did you get the data from?

Ann
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Re: APOD: Cygnus: Bubble and Crescent (2023 Sep 04)

Post by AVAO » Tue Sep 05, 2023 6:01 am

Ann wrote: Tue Sep 05, 2023 2:54 am
AVAO wrote: Mon Sep 04, 2023 3:52 pm
alex555 wrote: Mon Sep 04, 2023 9:23 am The star responsible for Crescent Nebula seems to be the bright point roughly in the middle but on the other hand for Bubble, we cannot clearly see the star which is the cause.

Alex

The blue star in the center is a White Dwarf candidate. :brr:

PanSTARRS DR1 PN G075.5+01.7 jac berne (flickr)
Thanks a bunch for identifying it for us, AVAO (or should I say Jac?)! Indeed, unless the the central star of a planetary nebula is very dust-reddened, it should always be identifyable by its striking blue color - which, of course, represents extremely hot temperatures, not biting cold!!!

It's a great picture, like all the pictures you post here. You created it yourself? Where did you get the data from?

Ann
ThanX Ann

Jac is fine ;-) ...
AVAO is a very small club of astrophilic citizen scientists in zurich switzerland. (AVAO - Artistic Illustration Technologies for the Hyper Realistic Spatial Visualisation of Astronomical Objects) I'm only pursues the goal of visually supporting the discussions in the APOD chat myself. In the images, specific details are visually enhanced artistically, which is not permitted in a direct scientific context. I'm not a professional astrophysicist myself, but sees me as a citizen scientist who conducts artistic research in the field of astronomy as a hobby. The goal is to specifically reinforce important image content with artistic means and thus make it apparent. But usually the pictures (in kind of a free artistic interpretation of the scientific data) in my posts are the result of my own research and analysis. The image today is a combination from the PanSTARRS DR1 survey with the blue central star with the NOIRLab observation from 2009, where you can also see the bubble-structure around for better orientation.

Image
Close up original cutout from the PanSTARRS DR1 survey

And yesss - The smilie was a fail - but a fail in the right color :brr:

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Re: APOD: Cygnus: Bubble and Crescent (2023 Sep 04)

Post by starsurfer » Tue Sep 05, 2023 10:13 pm

johnnydeep wrote: Mon Sep 04, 2023 8:47 pm
APOD Robot wrote: Mon Sep 04, 2023 4:07 am Image Cygnus: Bubble and Crescent

Explanation: As stars die, they create clouds. Two stellar death clouds of gas and dust can be found toward the high-flying constellation of the Swan (Cygnus) as they drift through rich star fields in the plane of our Milky Way Galaxy. Caught here within the telescopic field of view are the Soap Bubble (lower left) and the Crescent Nebula (upper right). Both were formed at the final phase in the life of a star. Also known as NGC 6888, the Crescent Nebula was shaped as its bright, central massive Wolf-Rayet star, WR 136, shed its outer envelope in a strong stellar wind. Burning through fuel at a prodigious rate, WR 136 is near the end of a short life that should finish in a spectacular supernova explosion. Discovered in 2013, the Soap Bubble Nebula is likely a planetary nebula, the final shroud of a lower mass, long-lived, Sun-like star destined to become a slowly cooling white dwarf. Both stellar nebulas are about 5,000 light-years distant, with the larger Crescent Nebula spanning about 25 light-years across. Within a few million years, both will likely have dispersed.
So the Soap Bubble Nebula was not discovered in 2013, as the Discovered in 2013 link text says, but in 2008, as the Bubble Nebula link content says:
In fact, amateur astronomer Dave Jurasevich identified it as a nebula on 2008 July 6
And this is confirmed by the Discovered in 2013 link content as well. But it was given an official designation in 2013 as that link says:
LATEST NEWS: On July 26, 2013 the Centre de Donnees Astronomiques de Strasbourg (CDS), the
world referenece database for the identification of astronomical objects and host to the SIMBAD
on-line database, officially designated PN G75.5+1.7 as Ju1 (Jurasevich 1).
Yeah you're right, the planetary nebula was discovered in 2008 by Dave Jurasevich and given the name of Ju 1 in 2013. For some reason a scientific paper on this has never been published.

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Re: APOD: Cygnus: Bubble and Crescent (2023 Sep 04)

Post by everettcade » Thu Sep 07, 2023 4:04 am

The two circle white ones in the picture are stellar death clouds, right? How about the Swangeometry dash subzero? I don't know well about this constellation. In your images, is there it?

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Re: APOD: Cygnus: Bubble and Crescent (2023 Sep 04)

Post by starsurfer » Thu Sep 21, 2023 10:32 pm

This previous APOD has the correct discovery year.