APOD: MWC 922: The Red Square Nebula (2011 Mar 23)

[APOD Robot]

MWC 922: The Red Square Nebula

Explanation: What could cause a nebula to appear square? No one is quite sure. The hot star system known as MWC 922, however, appears to be embedded in a nebula with just such a shape. The above image combines infrared exposures from the Hale Telescope on Mt. Palomar in California, and the Keck-2 Telescope on Mauna Kea in Hawaii. A leading progenitor hypothesis for the square nebula is that the central star or stars somehow expelled cones of gas during a late developmental stage. For MWC 922, these cones happen to incorporate nearly right angles and be visible from the sides. Supporting evidence for the cone hypothesis includes radial spokes in the image that might run along the cone walls. Researchers speculate that the cones viewed from another angle would appear similar to the gigantic rings of supernova 1987A, possibly indicating that a star in MWC 922 might one day itself explode in a similar supernova.

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[Keina]

It must be Route of Ages

[kapri]

Interesting:While the text behind the first "cone" link seems to be the outcome of a strange brain, the second cone link shows a pretty explanantion for the state of the universe right now and how a cone can be used to explain cosmology
Thanks!

[Jayarava]

Two water droplets back to back? Or a strobe shot of an orange being shot? Or a head on collision?

[JohnD]

So unusual? Or rather, not unique?
See: Boomerang nebula apod.nasa.gov/apod/ap071228.html
Henize 3 401: http://www.astronet.ru/.../h3401_hst_big.jpg.html
which like the Ant Nebula apod.nasa.gov/apod/ap050501.html may be older exmaples of the same phenomenon.

Gomez's Hamburger may show a mechanism: apod.nasa.gov/apod/ap020807.html
Planetary dust ring prevents gas expansion in all directions.
But this one is a very precise and focussed gas ejection!

John

[Starburst]

Strange shape for a nebula...

Couldn't it be a light distorsion cause by a massive object?

[Indigo_Sunrise]

Has one of the links from the description changed? Or maybe been updated? I believe it was one of the "MWC 922" links. (IIRC, the first?) But when I clicked it initially, it took me to a page that had some (really great!) graphics that helped me to visualize and better understand how this nebula can look the way it does. But now when I click that link, it takes me to a page that has a brief synopsis of an article that requires signing in to read it completely......
Bummer, because I was hoping to get to read the initial page in depth.

Anyone else have this happen to them?

Very interesting image, btw!

[owlice]

Yes, I got the same thing. Try this, which is I suspect the short version:
http://ao.jpl.nasa.gov/Palao/Publicatio ... Nebula.pdf

Or maybe this: http://www.physics.usyd.edu.au/~gekko/redsquare.html

Or this: http://www.sciencemag.org/content/316/5 ... siteid=sci

[What Is It]

Well, another mystery at NASA. Is there anything that they can answer? Everything is a mystery, from this Red Square Nebula , to black holes, to how did the earth form. I would say NASA gets an F for science. Go back to school!

[Chris Peterson]

:oops: Well, another mystery at NASA. Is there anything that they can answer? Everything is a mystery, from this Red Square Nebula , to black holes, to how did the earth form. I would say NASA gets an F for science. Go back to school!

A "mystery" doesn't mean that nothing is known. It only means that an answer isn't certain- which describes most interesting science. And for what it's worth, today's image and the associated scientific analysis have nothing to do with NASA.

[neufer]

Click to play embedded YouTube video.

Click to play embedded YouTube video.

[neufer]

http://apod.nasa.gov/apod/ap100614.html

Hubble Space Telescope ACS image. Broadband red light is shown in red, H-alpha emission in blue

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<<The Red Rectangle Nebula, so called because of its red color and unique rectangular shape, is a protoplanetary nebula near the Monoceros constellation. Also known as HD 44179, the nebula was discovered in 1973 during a rocket flight associated with the AFCRL Infrared Sky Survey called Hi Star. The binary system at the center of the nebula was first discovered by Robert Grant Aitken in 1915.

Diffraction-limited speckle images of it in visible and near infrared light reveal a highly symmetric, compact bipolar nebula with X-shaped spikes which imply toroidal dispersion of the circumstellar material. The central binary system is completely obscured, providing no direct light.

Exciting information was reported at the 203rd Meeting of the American Astronomical Society in January 2004 by a team led by A. Witt of the University of Toledo, Ohio, who discovered the spectral signatures of the polycyclic aromatic hydrocarbons anthracene and pyrene in the ultraviolet light emitted by the nebula - potentially vital organic molecules for the formation of life. Until recently, it was thought that the ultraviolet light would quickly destroy these hydrocarbons; the fact that the hydrocarbons still exist today has been explained by recently discovered molecular forces.

A likely explanation for its symmetry is that the central star - actually a close pair of stars - is surrounded by a thick dust torus which pinches the otherwise spherical outflow into tip-touching cone shapes. Because we view the torus edge-on, the boundary edges of the cone shapes seem to form an X. The distinct rungs suggest the outflow occurs in fits and starts. About 2,300 light-years away toward the constellation Monoceros, the Red Rectangle Nebula should be transformed into a planetary nebula as its cool central star becomes a hot white dwarf over the next few thousand years.

The Hubble Space Telescope has revealed a wealth of new features in the Red Rectangle that cannot be seen by ground-based telescopes looking through Earth's turbulent atmosphere. The origins of many of the features in this dying star still remain hidden or even outright mysterious, some are well explained by theorists like the Dutch scientist Vincent Icke from Leiden University in the Netherlands. In 1981 Vincent Icke and collaborators showed that a spherical gas ejection from a dying star hitting a dust torus would give rise to shocks that can produce cone-like outflows similar to the two cones seen in this nebula. Of the many different parameters in Vincent Icke’s calculations, only the density of the gas and the dust are observed in the nebula.>>

[orin stepanek]

I really liked this unique nebula! It's probably would look round if you could see it from the ends. Saved it to my wallpaper collection!

[moonstruck]

Aww the wonders of the universe. This is a beautiful happening out there.

[yasgur]

Most of the background stars look ovate and pointed either toward or away from the nebula. If they all pointed in the same direction, I'd just write it off to a short time lapse. Is this some other function of the camera work?

[NoelC]

Hubble Space Telescope ACS image. Broadband red light is shown in red, H-alpha emission in blue

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Thank you, neufer, for that.

Noting the several (two? multiple?) diffraction spikes emanating from the central region, is this just that the bright central part has knots of particularly strong brightness, or has the Hubble resolved multiple stars in there?

-Noel

[Indigo_Sunrise]

owlice, thanks for the links. WRT the third one you provided, I'm still getting a request for sign-up in order to read it, though.
The second link you list has the graphics I was looking for - thanks! (I guess I didn't scroll down enough earlier. )

But what an interesting image! I do wonder though, why it appears rectangular instead of circular, if it is conically(??) shaped...? (As the graphics midway down the page seem to suggest. I could be interpreting the diagrams incorrectly, though.)

[alphachapmtl]

Well, another mystery at NASA. Is there anything that they can answer? Everything is a mystery, from this Red Square Nebula , to black holes, to how did the earth form. I would say NASA gets an F for science. Go back to school!

I'm waiting for your explanations of all and every things...

[Beyond]

It isn't really square, but it looks so good - Who Cares??

[dlajuett]

I notice that one possibility for some of the stranger sights of the cosmos is never brought up, normally: might, just might, one or more of the strangest phenomena be not natural, but in fact artificial? The result of some unknowable alien super-experiment on a star? Just asking.

Your theory is crazy, but it's not crazy enough to be true.
Niels Bohr

Read more: http://www.brainyquote.com/quotes/quote ... z1HRtieyXH

[rstevenson]

I notice that one possibility for some of the stranger sights of the cosmos is never brought up, normally: might, just might, one or more of the strangest phenomena be not natural, but in fact artificial? The result of some unknowable alien super-experiment on a star? Just asking.

Such ideas may not be disucussed here, it being contrary to the rules. However, if we ever have solid data -- say, astronomers spot a cepheid variable blinking on/off in Morse code -- then you can rest assured it would be discussed here.

Rob

[lankytom]

It is not hard to visualize the 'Red Square Nebula' as the result of plasma jets. I can see how that can occur and give the image from our angle. I'll bet the folks at Los
Alamos labs could simulate it. I'd do it, but I don't have that kind of program on my IMAC - yet.

[neufer]

It is not hard to visualize the 'Red Square Nebula' as the result of plasma jets. I can see how that can occur and give the image from our angle. I'll bet the folks at Los Alamos labs could simulate it. I'd do it, but I don't have that kind of program on my IMAC - yet.

Plasma jets from a precessing star was my first guess as well.

They seem to prefer sculpted spherical flow.

[Apple]

Or, it's not a nova.

[garry]

The picture shows a double cone focused on a star, not a square.A square shape is not found in nature. There are similar nebulae with the characteristics of double cones. But what is interesting is that in similar double cone nebulae is that when the cone is extended away from the star at the focus point, the sides of the "cones" become parallel. So, not the mythical black hole or neutron star can do this. Not plasma jets as the distance the cone reaches could not be provided by the star's internal source of power. If one observes with common sense, what one sees in this picture, (the rarest item in the universe), an alternative explanation can be seen. But can we see it?