APOD: The Necklace Nebula (2010 Nov 03)

[dougettinger]

G'day

Supernova is where a star explodes completely and a Nova is where the solar envelope is ejected to some degree.

Doug asked the questiion

What possible mechanism causes polar jets in the case of the Necklace Nebula or a dying star ? These jets, according to the article, occurred 5000 years prior to the nebula cloud being created.

What are the possible candidate types for the two stars orbiting in less than two days ? Would not the lesser mass body be eaten by the larger mass ? Could a neutron star feed on a white dwarf ?

The power for such jets lies in the dynamic properties of Nuclear phase transitions within compact Nuclear matter and their ability to form spontaneous dipolar jets with enough stability to form jets that may go for light years.

G'day, Harry. I am trying to better understand the dipolar jets of both protostars and dying stars. What is common to both is that material falls inward mostly by spinning plasma in the equatorial regions. The particles are being pushed together but are resisting due to their inherent magnetic properties. Time is needed to arrange the particles into more compact arrangements, but due to irregular densities many magnetized particles pop out at the center similar to squeezing a balloon around its girth. Until enough time is acquired to re-arrange the particles into higher compaction (elements with higher atomic numbers), the particles especially electrons are ejected at both poles of the imploding star by both pressure and electrical energy.

These are words that I can understand. Is this concept close to what you stated?


I am still anxious to know what kind of stars were left in the aftermath of the creation of the Necklace Nebula (?)

Doug Ettinger
Pittsburgh, PA

[Chris Peterson]

G'day, Harry. I am trying to better understand the dipolar jets of both protostars and dying stars. What is common to both is that material falls inward mostly by spinning plasma in the equatorial regions. The particles are being pushed together but are resisting due to their inherent magnetic properties. Time is needed to arrange the particles into more compact arrangements, but due to irregular densities many magnetized particles pop out at the center similar to squeezing a balloon around its girth. Until enough time is acquired to re-arrange the particles into higher compaction (elements with higher atomic numbers), the particles especially electrons are ejected at both poles of the imploding star by both pressure and electrical energy.

These are words that I can understand. Is this concept close to what you stated?

Neither of the papers Harry listed are particularly relevant to your questions. But I think your understanding is pretty good, as outlined above. The key concept is that the star has a powerful magnetic field, and the twisting of this field- especially by a rapidly rotating star- is what fundamentally drives jet formation. It has nothing to do with matter in any sort of exotic state.

I am still anxious to know what kind of stars were left in the aftermath of the creation of the Necklace Nebula (?)

Presumably, the progenitor star is still undergoing hydrogen fusion in its outer shell, or possibly has just begun cooling and is heading towards its white dwarf phase. The second star is unlikely to have changed from whatever it was before the progenitor star shed its envelope.

[bystander]

Neither of the papers Harry listed are particularly relevant to your questions.

As has been noted many times before, the papers Harry posts are seldom relevant. I could do as well by going to the arXiv site, searching on a few key words, and selecting papers at random. I had thought we had gotten past that, but it seems I was mistaken.

[dougettinger]

G'day, Harry. I am trying to better understand the dipolar jets of both protostars and dying stars. What is common to both is that material falls inward mostly by spinning plasma in the equatorial regions. The particles are being pushed together but are resisting due to their inherent magnetic properties. Time is needed to arrange the particles into more compact arrangements, but due to irregular densities many magnetized particles pop out at the center similar to squeezing a balloon around its girth. Until enough time is acquired to re-arrange the particles into higher compaction (elements with higher atomic numbers), the particles especially electrons are ejected at both poles of the imploding star by both pressure and electrical energy.

These are words that I can understand. Is this concept close to what you stated?

Neither of the papers Harry listed are particularly relevant to your questions. But I think your understanding is pretty good, as outlined above. The key concept is that the star has a powerful magnetic field, and the twisting of this field- especially by a rapidly rotating star- is what fundamentally drives jet formation. It has nothing to do with matter in any sort of exotic state.

I am still anxious to know what kind of stars were left in the aftermath of the creation of the Necklace Nebula (?)

Presumably, the progenitor star is still undergoing hydrogen fusion in its outer shell, or possibly has just begun cooling and is heading towards its white dwarf phase. The second star is unlikely to have changed from whatever it was before the progenitor star shed its envelope.

A white dwarrf may draw material from a close binary neighbor. When one binary star dies why is not its material captured by the other binary star when it sheds its outer layers ?

Doug Ettinger
Pittsburgh, PA

[mpharo]

The Necklace Nebula (2010 Nov 03)

This little nebula has at least 13 orange stars in a circle with a star at the center. The necklace has a light blue surrounding and a bright green glow around it's small circumference. I like that contrast of colors. I wonder what the two dark blue circles are in the center.

Michael Pharo

[harry]

G'day

It seems that science is restricted.

The papers that I posted are mainstream and are not backyard papers.

Chris Peterson said

Neither of the papers Harry listed are particularly relevant to your questions. But I think your understanding is pretty good, as outlined above. The key concept is that the star has a powerful magnetic field, and the twisting of this field- especially by a rapidly rotating star- is what fundamentally drives jet formation. It has nothing to do with matter in any sort of exotic state.

Totally wrong.

Than I would advice a bit of research. Maybe arXiv or NASA ADS

The questions are:

What creates the magnetic fields?

What rotates a star?

What creates a stable jet?

The following paper is just part of the science journey:

http://arxiv.org/abs/1010.3861
Steady jets and transient jets: observational characteristics and models

Authors: M. Massi
(Submitted on 19 Oct 2010)

Abstract: Two types of radio emission are observed from X-ray binaries with jets. They have completely different characteristics and are associated with different kinds of ejections. One kind of emission has a flat or inverted spectrum indicating optically thick self-absorbed synchrotron emission; the second kind of emission corresponds to an optically thin "transient" outburst. The flat or inverted spectrum covers the whole radio band and has been established also at millimeter and infrared wavelengths. When this kind of radio emission is spatially resolved it appears as a continuous jet, the so-called "steady jet". In contrast, transient jets associated with optically thin events are resolved as "plasmoids" moving at relativistic speeds away from the center of the system. The most important point is that the two kinds of radio emission and their corresponding types of ejections seem to be related to each other; the optically thin outburst that characterizes the transient jet occurs after an interval of emission with flat/inverted spectrum. Two different models successfully describe the two jets: a conical flow and shocks. The conical outflow describes the continuous jet and internal shocks in a continuous pre-existing outflow describe the "plasmoids" of the transient jet. The internal shocks in the outflow are thought to originate from a new population of very fast particles. Three open issues are discussed: is magnetic reconnection the physical process generating the new population of very fast particles? Is that part of the continuous jet called "core" destroyed by the transient jet and its associated shocks? Can we extrapolate these results from steady and transient jets in X-ray binaries to radio loud AGNs?
T

[bystander]

The papers that I posted are mainstream and are not backyard papers.
...
Then I would advise a bit of research. Maybe arXiv or NASA ADS

Just because something is in arXiv, does not mean it is mainstream.
And, if it is in arXiv, it is probably also in adsabs.harvard.edu. Again,
no guarantee it is mainstream or even in a peer reviewed journal.

Just because you say it's relevant does not necessarily make it so.

[Chris Peterson]

The papers that I posted are mainstream and are not backyard papers.

I didn't say there was anything wrong with the science in the papers. I said they weren't relevant to the question being asked. One of the papers had to do with galactic jets, and the other to do with magnetic reconnection. Neither has anything to do with how a dying red dwarf might have jet structures that modulate the ejection of shells.

[Chris Peterson]

This little nebula has at least 13 orange stars in a circle with a star at the center. The necklace has a light blue surrounding and a bright green glow around it's small circumference. I like that contrast of colors. I wonder what the two dark blue circles are in the center.

You are misinterpreting the image. There is a pair of stars in the center, which can't be resolved. The spots around that are not stars, but regions of hot gas- very diffuse, but dense compared with the surrounding areas.

[Chris Peterson]

A white dwarrf may draw material from a close binary neighbor. When one binary star dies why is not its material captured by the other binary star when it sheds its outer layers ?

Any star can capture material from a close binary. In this case, it is unlikely that the progenitor has had enough time to become a white dwarf yet. It is probably still fusing hydrogen. Even if hydrogen fusion has stopped, the star is probably still in the process of consolidating into a white dwarf.

I'm not positive, but I suspect that the careful photometry involved in determining that there is actually a binary progenitor would have detected signs of material falling inwards in an accretion disc.

[owlice]

This thread has gathered some posts that are outside the subject matter of the Starship Asterisk. I would like to remind posters, whether registered or guest, that this is a mainstream science board. Please note the following, which is Rule 15 in the Handbook:

Alternative Theories and Conspiracy Theories
This board concentrates on the mainstream or consensus view of cosmology. Alternative theories and conspiracy theories are not discussed here. We may decide to allow limited discussion of these at some later date. For now, however, we ask that you take these discussions to other boards that allow such discussions, such as The BAUT Forum.

Thanks for your cooperation.

[dougettinger]

A white dwarrf may draw material from a close binary neighbor. When one binary star dies why is not its material captured by the other binary star when it sheds its outer layers ?

Any star can capture material from a close binary. In this case, it is unlikely that the progenitor has had enough time to become a white dwarf yet. It is probably still fusing hydrogen. Even if hydrogen fusion has stopped, the star is probably still in the process of consolidating into a white dwarf.

I'm not positive, but I suspect that the careful photometry involved in determining that there is actually a binary progenitor would have detected signs of material falling inwards in an accretion disc.

I did not make myself well understood. When the progenitor star begins to shed its outer layers, why does not the neighboring binary capture some or all of these materials being shed ?

What is owlice reference in the following submission ?

Doug Ettinger
Pittsburgh, PA

[neufer]

A white dwarf may draw material from a close binary neighbor.
When one binary star dies why is not its material captured by the other binary star when it sheds its outer layers ?

If star A easily ejects material at high velocity then it is unlikely that
any neighboring star B will pick up more of that material than it will shed from the blast.

[owlice]

What is owlice reference in the following submission ?

A number of posts had been made espousing alternate theories of cosmology (as in, not generally accepted by scientists in the field), which are not allowed here. They were (re)moved, and my post is an attempt to head off any other such posts.

[Chris Peterson]

I did not make myself well understood. When the progenitor star begins to shed its outer layers, why does not the neighboring binary capture some or all of these materials being shed ?

No doubt it captures some tiny bit. But the ejection of material is roughly spherical, and the binary companion represents only a tiny fraction of the solid angle around the progenitor. So it isn't going to intercept much. The ejected material certainly exceeds the escape velocity of the system, so it isn't going to end up in orbit around the companion, either.

[dougettinger]

Thanks for your simple but very adequate reply. Since I have you in this frame of mind, what do you suppose happens to a neighboring binary when the progenitor is a supernova ? Is the star swept away in the blast? Is it destroyed ? Or does it maintain some orbit and keep fusing ?

Doug Ettinger
Pittsburgh, PA

[Chris Peterson]

Thanks for your simple but very adequate reply. Since I have you in this frame of mind, what do you suppose happens to a neighboring binary when the progenitor is a supernova ? Is the star swept away in the blast? Is it destroyed ? Or does it maintain some orbit and keep fusing ?

At least in some cases (maybe most) the companion star will survive, largely unaltered, when the other star in the system goes supernova. This does depend on the type of supernova- some are the result of mass transfer between two companions, which can destroy or alter the one feeding the supernova.

[dougettinger]

Do astronomers have actual evidence of a binary pair where one was known to have been a supernova either Type Ia or Type II due to its remnants ? The Necklace Nebula is obviously evidence for a binary pair after one entered the red giant phase.

Doug Ettinger
Pittsburgh, PA

[Chris Peterson]

Do astronomers have actual evidence of a binary pair where one was known to have been a supernova either Type Ia or Type II due to its remnants ? The Necklace Nebula is obviously evidence for a binary pair after one entered the red giant phase.

Yes. This one is very cool because it's such a historical supernova.

[neufer]

Do astronomers have actual evidence of a binary pair where one was known to have been a supernova either Type Ia or Type II due to its remnants ? The Necklace Nebula is obviously evidence for a binary pair after one entered the red giant phase.

Yes. This one is very cool because it's such a historical supernova.

Centre of Tycho's supernova remnant. The star marked as 'G' is identified as the companion G0–G2 star of Tycho Brahe´s 1572 supernova. Since 1572, Tycho G has moved 2.6 arcseconds south.

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The Companion Star to Type Ia Tycho Brahe's 1572 Supernova

<<The brightness of type Ia supernovae, and their homogeneity as a class, makes them powerful tools in cosmology, yet little is known about the progenitor systems of these explosions. They are thought to arise when a white dwarf accretes matter from a companion star, is compressed and undergoes a thermonuclear explosion. Unless the companion star is another white dwarf (in which case it should be destroyed by the mass-transfer process itself), it should survive and show distinguishing properties.

Tycho’s supernova is one of only two type Ia supernovae observed in our Galaxy, and so provides an opportunity to address observationally the identification of the surviving companion.

A team of astronomers carried out an imaging and spectroscopic survey using ISIS, UES and the Auxiliary Camera on the WHT of the central region of Tycho's supernova remnant, around the position of the explosion. The analysis of the data excluded red giants as the mass donor of the exploding white dwarf. However, they found a type G0–G2 star, similar to our Sun in surface temperature and luminosity (but lower surface gravity), moving at more than three times the mean velocity of the stars at that distance, which they claim to be the surviving companion of the supernova.>>

Building a 136 km/s Tycho “G” Pro

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Building a Tyco “G” Pro -- a hot TycoPro with traction magnets and other performance mods...! by Terry Flynn

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[neufer]

The Necklace Nebula

Explanation: The small constellation Sagitta sports this large piece of cosmic jewelry, dubbed the Necklace Nebula.

[dougettinger]

Do astronomers have actual evidence of a binary pair where one was known to have been a supernova either Type Ia or Type II due to its remnants ? The Necklace Nebula is obviously evidence for a binary pair after one entered the red giant phase.

Yes. This one is very cool because it's such a historical supernova.

I want to thank you both, Chris and Art, for providing me with an excellent example of two survivors after a Type Ia Supernova (Tycho Brahe SN). I will press on if you do not mind. Is there a good example of surviving binaries after a Type II Supernova ? And I am referring to a recent Type II Supernova where the remnant can still be observed. I suppose that any binary with a neutron star or black hole (hopefully you can give me an example) is the result of a Type Ib, Ic, or II Supernova.

My limited experiences are constraining my thinking. Whenever I think of explosions here on Earth, I visualize everything being destroyed in its vicinity. I am trying to escape my earthbound conceptions. Thanks for helping me.

Doug Ettinger
Pittsburgh, PA