Starship Asterisk*

The Soap Bubble Nebula

Explanation: Adrift in the rich star fields of the constellation Cygnus, this lovely, symmetric nebula was only recognized a few years ago and does not yet appear in some astronomical catalogs. In fact, amateur astronomer Dave Jurasevich identified it as a nebula on 2008 July 6 in his images of the complex Cygnus region that included the Crescent Nebula (NGC 6888). He subsequently notified the International Astronomical Union. Only eleven days later the same object was independently identified by Mel Helm at Sierra Remote Observatories, imaged by Keith Quattrocchi and Helm, and also submitted to the IAU as a potentially unknown nebula. The nebula, appearing on the left of the featured image, is now known as the Soap Bubble Nebula. What is the newly recognized nebula? Most probably it is a planetary nebula, a final phase in the life of a sun-like star.

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Do the planetary nebulas we see in the sky typically represent the final phase of a Sun-like star?

If a star like the Sun typically lives for 10-12 billion years, then maybe most planetaries represent the death shrouds of stars that are (slightly) more massive and short-lived than the Sun.

Ann

I think it is misidentified. Not a planetary nebula. A gas bubble. Like the Bubble Nebula. Does not look like a star that has thrown off a shell of gas....that has more material, and colors, and looks like an explosion.
This looks like a stable bubble.

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Ann wrote:Do the planetary nebulas we see in the sky typically represent the final phase of a Sun-like star?

Wikipedia says that "planetary nebulae seemingly only occur at the end of the lives of intermediate and low mass stars between 0.8 M⊙ to 8.0 M⊙." So I guess it depends on what you mean by "Sun-like." Given the age of the universe, I suppose it's safe to assume that stars at the lower end of that range are not yet the majority of the source stars for the planetary nebulas we're seeing.

Rob

At least at the end of The Sun's life, we shall be a pretty entry in someone's Planetary Nebula catalog....

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Boomer12k wrote:I think it is misidentified. Not a planetary nebula. A gas bubble. Like the Bubble Nebula. Does not look like a star that has thrown off a shell of gas....that has more material, and colors, and looks like an explosion.
This looks like a stable bubble.

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A stable bubble? Really? Formed and maintained by space fairies??

No.....maintained by its own mass...Density and volume. This is a very rounded shape. Sharp lines definiing the edges....way different than ANY Planetary Nebula....The Ring Nebula, for example.

Look up The Bubble Nebula....Caldwell 11... C 11....

There is no central star in this bubble...there IS a central star in Planetary Nebulae.....like there are for Supernova....

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Boom, you seem to be saying that a nicely symetrical bubble-like nebula cannot occur as the result of the death throws of a star. But it can. All it requires is that the forces are not thrown out of balance by something else -- a binary companion or close-in hot-Jupiter, for example, either of which could cause the nebula to take on an odd shape. So if this is indeed a planetary nebula resulting from the near-final processes of an old star, its simple shape may just mean that the star had few, small and distant planets -- or none at all, so its gaseous envelope was puffed off without disturbance.

As for whether there is a central star here, the most I could say from just this picture is that I can't see which star is the central star. I wouldn't state, just from that, that there is no central star. (But I would go looking for it, just to be sure.)

Rob

Boomer12k wrote:I think it is misidentified. Not a planetary nebula. A gas bubble. Like the Bubble Nebula.

I don't think so. Such bubbles are produced by Wolf-Rayet stars, because that's the only way to get the high velocity stellar wind required to carve them out rapidly enough to sustain such structure. There are clearly no such stars present here.

This looks like a stable bubble.

Not sure what you mean by that. A bubble of gas cannot be stable. Whether produced by Wolf-Rayet winds, or by expulsion from a star, all bubbles are extremely transient phenomena.

Looks like the initial framework for a Dyson Sphere.

The Soap Bubble Nebula looks a bit like the ring I saw in the evening sky on January 1st:
http://asterisk.apod.com/viewtopic.php? ... 50#p237506
(Scroll down a bit, the picture is at the end of the post by Sandgirl.)

Florian wrote:The Soap Bubble Nebula looks a bit like the ring I saw in the evening sky on January 1st:
http://asterisk.apod.com/viewtopic.php? ... 50#p237506
(Scroll down a bit, the picture is at the end of the post by Sandgirl.)

I was wondering about that photo. Was it something you saw with your eyes or something that only appeared after you used the camera? It lines up really well with the various lens reflections present in the image.

was wondering about that photo. Was it something you saw with your eyes or something that only appeared after you used the camera? It lines up really well with the various lens reflections present in the image.

Except for the lens reflections the picture shows what I saw with my eyes. The ring was there. The reflections are from nearby streetlights. I should have paid more attention to lights on the ground when I shot the photo. I I didn't have a tripod handy, so this is a hand-held 1-second exposure at f/2, ISO 12,800. I did some sharpening and adjusted the contrast in Photoshop to make the ring easier to see. In reality it was not very bright.

What was done to the image so that we are able to see the Soap Bubble Nebula[?] appearing here as a faint bluish haze and ring?
Is it a reflection nebula? What would be the source? Is it ionized or heated?

MarkBour wrote:What was done to the image so that we are able to see the Soap Bubble Nebula[?] appearing here as a faint bluish haze and ring?
Is it a reflection nebula? What would be the source? Is it ionized or heated?

It's [OIII] emission, so ionized http://en.wikipedia.org/wiki/Doubly_ionized_oxygen

MarkBour wrote:What was done to the image so that we are able to see the Soap Bubble Nebula[?] appearing here as a faint bluish haze and ring?
Is it a reflection nebula? What would be the source? Is it ionized or heated?

It is an [OIII] emission nebula. This image is constructed from two narrowband channels, H-alpha displayed as orange and [OIII] displayed as blue. The ionization source would be the parent star, which based on color and location I would say is this one:

Chris Peterson wrote:

MarkBour wrote:What was done to the image so that we are able to see the Soap Bubble Nebula[?] appearing here as a faint bluish haze and ring?
Is it a reflection nebula? What would be the source? Is it ionized or heated?

It is an [OIII] emission nebula. This image is constructed from two narrowband channels, H-alpha displayed as orange and [OIII] displayed as blue. The ionization source would be the parent star, which based on color and location I would say is this one:

soapbubble-center.jpg

Thanks, Chris. Note that a good RGB image would single out the parent star more clearly. An RGB + U image would do the job even better.

Ann

Ann wrote:Thanks, Chris. Note that a good RGB image would single out the parent star more clearly. An RGB + U image would do the job even better.

Yes, but with the two bands chosen, a very hot star will be quite blue, which the star I've identified is. That, combined with the location very near the center gives me some confidence it is the progenitor star.

Although rare, spherical planetary nebulae do exist although it is strange that the majority exhibit bipolar morphology, which is likely due to a binary central star. Quite a few low surface brightness spherical planetary nebulae have been discovered in the past decade as part of either the amateur Deep Sky Hunters initiative as well as professional Ha surveys such as SHS (with the MASH PN project) and IPHAS. The fact that many of these are very faint suggests they are fairly old and evolved with ages of possibly more than 10 000 years.

APOD Robot wrote:does not yet appear in some astronomical catalogs.

This planetary nebula was included in professional databases as Ju 1 a few years ago.

I've noticed that Dr Travis Rector's research interests are listed in the University of Alaska Anchorage website as "Astronomy, Astrophysics, Snow Physics". Snow Physics sounds like a fun science!

starsurfer wrote:Although rare, spherical planetary nebulae do exist although it is strange that the majority exhibit bipolar morphology, which is likely due to a binary central star.

I wonder if it's certain this is actually a spherical structure? After all, the Ring Nebula was assumed for years to be a bubble, before it was realized that it was actually a bipolar structure. From certain orientations it isn't easy to distinguish the two.

Chris Peterson wrote:

starsurfer wrote:Although rare, spherical planetary nebulae do exist although it is strange that the majority exhibit bipolar morphology, which is likely due to a binary central star.

I wonder if it's certain this is actually a spherical structure? After all, the Ring Nebula was assumed for years to be a bubble, before it was realized that it was actually a bipolar structure. From certain orientations it isn't easy to distinguish the two.

Some nebulas exhibit both spherical and bipolar structures. The Egg Nebula, for example. It has it all. A ring of dust, polar ejections, concentric rings (which I suspect are sphere shells) and spotlights!

geckzilla wrote:

Chris Peterson wrote:

starsurfer wrote:Although rare, spherical planetary nebulae do exist although it is strange that the majority exhibit bipolar morphology, which is likely due to a binary central star.

I wonder if it's certain this is actually a spherical structure? After all, the Ring Nebula was assumed for years to be a bubble, before it was realized that it was actually a bipolar structure. From certain orientations it isn't easy to distinguish the two.

Some nebulas exhibit both spherical and bipolar structures. The Egg Nebula, for example. It has it all. A ring of dust, polar ejections, concentric rings (which I suspect are sphere shells) and spotlights!

Thanks for the info, and a great question. We can see various "wisps" in addition to the outer edge which grows more opaque as one approaches the edge. It really gives the impression of being spherical. Can one determine the distance position of various stars in the region of the bubble, and can one tell whether any given star appears to be "behind" various amounts of the OIII?

I'm reminded of the artist Felice Varini, who demonstrates some wonderful, surprising shapes that give the same 2-dimensional view. But there is a "most likely" 3-D shape, and astronomers probably have to go with that in general, right?

Ann wrote:

Chris Peterson wrote:

MarkBour wrote:What was done to the image so that we are able to see the Soap Bubble Nebula[?] appearing here as a faint bluish haze and ring?
Is it a reflection nebula? What would be the source? Is it ionized or heated?

It is an [OIII] emission nebula. This image is constructed from two narrowband channels, H-alpha displayed as orange and [OIII] displayed as blue. The ionization source would be the parent star, which based on color and location I would say is this one:

soapbubble-center.jpg

Thanks, Chris. Note that a good RGB image would single out the parent star more clearly. An RGB + U image would do the job even better.

Ann

An RGB image by Mel Helm is available that shows the central star very nicely. He is also one of the independent discoverers of this planetary nebula along with Keith Quattrocchi in the same year that Dave Jurasevich found it in, which was 2008. I'm surprised a scientific paper still hasn't been published but I guess science is slow.

Chris Peterson wrote:

starsurfer wrote:Although rare, spherical planetary nebulae do exist although it is strange that the majority exhibit bipolar morphology, which is likely due to a binary central star.

I wonder if it's certain this is actually a spherical structure? After all, the Ring Nebula was assumed for years to be a bubble, before it was realized that it was actually a bipolar structure. From certain orientations it isn't easy to distinguish the two.

We will all find out once the scientific paper is published! It is true that we can have an incorrect idea of the true morphology of planetary nebula due to projection effects along our line of sight and also only having a 2D view of a 3D structure. Another good example is the Helix Nebula, visually the main central structure looks quite round but I think this is a case of the pole of a bipolar structure directly facing us.