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Red Square Nebula (APOD 16 April 2007)

Posted: Mon Apr 16, 2007 4:41 am
by rigelan
That red square.

Wow, what a brilliant oddity!

Posted: Mon Apr 16, 2007 5:11 am
by Nilesh
this square view may be caused due to scattering of light from square shaped crystals.
micor-cristals may be present in the nebula which surrounds central star.
these crystals (if present) get properly alligned in presence of star's magnetic field and cause light to scatter & polarise in well defined direction.
this may cause nebular glow appear in sqare shape.
original shape of nebula may not be square but scatering & polarising in our direction may cause it "look" square.

this is my hypothesis- experts can please advice.

Diagnosis or prognosis?

Posted: Mon Apr 16, 2007 12:55 pm
by Axel
The caption says: "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." But the link provided about 1987A (APOD, 7 January 2007) tells us that the rings surrounding that object are a result of the supernova event. So which is it: do these rings appear before or after the big explosion?

Posted: Mon Apr 16, 2007 1:11 pm
by NoelC
To be accurate, the SN1987A inner and outer rings, which are many light-years from the star's position, were there well in advance of the star exploding, and the explosion shock led to a significant brightening of the "beads" of the inner ring(s).

Image

-Noel

red square nebula image has artifacts

Posted: Mon Apr 16, 2007 4:13 pm
by beepboop
This image has a lot of distortion (stars near the edges are elongated), and five of the bright stars show hexagonal spike pattern, possibly artifact of the optics. Can anybody comment on these artifacts?

Posted: Mon Apr 16, 2007 4:52 pm
by BMAONE23
Beepboop,
Interesting catch. Now that you mention it, all of the light sources (stars) in the image appear to be slightly elongated but forther, the elongations appear to radiate from the center of the image. (all stars point away from the nebula.) The nebula does appear to be an hourglass shape, like the shpe of SN1987a, that is viewed perfectly side on.

Sweeping up the ejecta

Posted: Mon Apr 16, 2007 6:43 pm
by gregg07
BMAONE23 wrote:Beepboop,
that is viewed perfectly side on.
Or maybe like a variation of the Hourglass Nebula (http://antwrp.gsfc.nasa.gov/apod/ap020615.html).

If a star has a thick dust ring (maybe even ones like the "Asteroid Belt", Kuyper Belt, and Oort cloud) and several large planets (perhaps even a 'hot jupiter'), wouldn't it build such a structure as the orbiting planets and dust belts sweep up gas and stellar ejecta?

Planets and Dust Rings

Posted: Mon Apr 16, 2007 6:51 pm
by gregg07
If our own star has a LOT OF stuff (say like a lot of asteroids, "THE" Main Asteroid belt, the Kuyper Belt, and the Oort Cloud) around it, like rings around Saturn, and if we had several large planets and minor planets and sub planets and (whatever they are called anymore) orbiting our sun, as we do, wouldn't they essentially sweep up a lot of solar ejecta - slowly creating this same kind of hourglass structure? And if our sun reaches the age when it begins to eject large quantities, turning into a planetary nebula, wouldn't it look sort of like this does, from the exactly correct point off to the side somewhere?

Re: red square nebula image has artifacts

Posted: Mon Apr 16, 2007 9:57 pm
by Chris Peterson
beepboop wrote:This image has a lot of distortion (stars near the edges are elongated), and five of the bright stars show hexagonal spike pattern, possibly artifact of the optics. Can anybody comment on these artifacts?
I think it's likely that the coma-like distortion of stars away from the nebula results because they are increasingly out of the isoplanatic zone of the adaptive optics system (assuming that the artificial guide star is located in front of the nebula). The field is 30 arcseconds wide- certainly large enough that outer stars will not be fully corrected. It may also result from the stars being outside the fully correctable region of the AO system, regardless of the theoretically correctable region size.

The hexagonal spike pattern is often present in Keck images. Presumably it is nothing more than the expected diffraction pattern produced by the hexagonal primary mirror array, and possibly also the secondary support structure.

This image has obviously been heavily processed to bring out detail, and such processing often emphasize otherwise more subtle optical artifacts like these.

Re: red square nebula image has artifacts

Posted: Mon Apr 16, 2007 10:56 pm
by beepboop
[quote="Chris Peterson"]
This image has obviously been heavily processed to bring out detail, and such processing often emphasize otherwise more subtle optical artifacts like these.[/quote]

I would conclude that the details of the image which we are looking for are as subtle as the optical artifacts which result from their measurement. The evidence of these artifacts unfortunately casts some doubt upon the intended interpretation.

Re: red square nebula image has artifacts

Posted: Mon Apr 16, 2007 11:09 pm
by Chris Peterson
beepboop wrote:I would conclude that the details of the image which we are looking for are as subtle as the optical artifacts which result from their measurement. The evidence of these artifacts unfortunately casts some doubt upon the intended interpretation.
Perhaps you are not accustomed to looking at images which have been processed to enhance specific detail (as opposed to processed for aesthetic purposes). There's really nothing in the evident artifacts that should be seen as seriously affecting the scientific value of the image. The artifacts are easily recognized by their regular appearance (and I'm sure the people using this image for more rigorous analysis are well aware of these artifacts and can treat them equally rigorously). The global structure of the nebula is much larger than any artifacts, and the fine detail seen in its structure, which may be on a similar scale to the artifacts, is very different in morphology.

Personally, I don't see anything about the artifacts that makes me think important elements seen in the image are false, nor anything that would argue against the interpretation suggested.

What structures shown in the image do you see as possibly false, and how would that affect the interpretation that we are seeing two cones of material?

Re: red square nebula image has artifacts

Posted: Tue Apr 17, 2007 3:08 am
by beepboop
Perhaps you are not accustomed to looking at images which have been processed to enhance specific detail ... What structures shown in the image do you see as possibly false, and how would that affect the interpretation that we are seeing two cones of material?
I don't doubt the validity of the conclusion. It is very interesting. I just feel that if the image is going to be "processed to enhance details", it would be even more compelling if it could have also been "processed to remove artifacts". I would have even rotated this image to produce a more conventional hourglass appearance, consistent with the interpretation.

Re: red square nebula image has artifacts

Posted: Tue Apr 17, 2007 3:59 am
by Chris Peterson
beepboop wrote:I don't doubt the validity of the conclusion. It is very interesting. I just feel that if the image is going to be "processed to enhance details", it would be even more compelling if it could have also been "processed to remove artifacts". I would have even rotated this image to produce a more conventional hourglass appearance, consistent with the interpretation.
Some APOD images were produced with aesthetics in mind. Some (like this) were produced with science in mind. Aside from the fact that there is no processing technique other than hand painting in Photoshop that can remove these minor artifacts, there is no motive for the scientists doing this work to attempt such processing. The artifacts don't interfere with their analysis, and in fact, removing them would violate the ethical standards of most journals. The researchers are better off spending their time analyzing the data, not making it prettier.

Posted: Tue Apr 17, 2007 7:46 am
by cdcdent
This looks like a double reflection

You get this effect with two mirrors at right angles (somewhat like a kaleidoscope)

I believe this is possibly the first double gravitational lens

The effect of each is at right angles to the other

I leave it to the mathematicians to expalin it better than me

Posted: Tue Apr 17, 2007 7:49 am
by cdcdent
This looks like a double reflection

You get this effect with two mirrors at right angles (somewhat like a kaleidoscope)

I believe this is possibly the first double gravitational lens

The effect of each is at right angles to the other

I leave it to the mathematicians to expalin it better than me

Posted: Wed Apr 18, 2007 8:15 am
by cdcdent
Could this be yet another Einstein Cross?

http://asterisk.apod.com/vie ... hp?t=10380

Posted: Wed Apr 18, 2007 1:46 pm
by Chris Peterson
cdcdent wrote:Could this be yet another Einstein Cross?

http://asterisk.apod.com/vie ... hp?t=10380
This object has nothing to do with gravitational lensing. Keep in mind that it's very close- just 5000 ly. We see gravitational lensing when massive distant galaxies bend the light of even more distant quasars.

The Red Square Nebula is just that- a nebula.

Posted: Wed Apr 18, 2007 4:42 pm
by kovil
[ihttp://www.americanscientist.org/content/AMSCI ... 27_646.jpg
Figure 6. Circularly polarized lightmghttp://www.americanscientist.org/content/AMSCI ... 27_646.jpg
Figure 6. Circularly polarized light][/img]

Well, that didn't work. I don't know how to transfer and insert and image yet. pardon.

The idea of the article is that starlight is reflected from small objects aligned by a local magnetic field, and this is causing the polarized light. We are correctly aligned by location to view it at just the right angle to see what we see.

Posted: Wed Apr 18, 2007 6:07 pm
by Andy Wade
How's this?

Image

(You just had some of the url text mixed in with your image tags)

Posted: Wed Apr 18, 2007 8:00 pm
by NoelC
I agree that the image itself is highly processed/enhanced, and thus looks a bit contrived. But I'm familiar with what Astroimages look like when overprocessed (e.g., by deconvolution), and this is not out of the ordinary.

-Noel

Posted: Wed Apr 18, 2007 8:27 pm
by kovil
Thanks very much Andy, that's it !

The perennial case of my not going far enough, I gave up too soon on figuring out why.

Posted: Thu May 03, 2007 11:05 am
by brachiopod
Is it just a coincidence that the artefact line passing roughly East-West through the the various bright sources in the photograph is in the same orientation as the southern edge of the eastern 'cone' and the northern edge of the western 'cone'?

Also, the distance from the center of the 'star' to the various advancing edges discernable in the photograph are not symmetrical about the (roughly) NW-SE symmetry plane.

The Red Square Nebula

Posted: Tue May 27, 2008 5:55 pm
by jesusfreak16
Does anybody have any ideas on how the Red Square Nebula(MWC 922) got its almost right angle corners?

http://antwrp.gsfc.nasa.gov/apod/ap070416.html

How did it originate?I believe it was made by intelligent design,but that's my belief.I'm not trying to make a big deal about this,but I think it would be interesting to see how others believe this nebula got its shape.
(In other words,I'm not trying to cause any debate,but merely to see other people's ideas.)

Posted: Tue May 27, 2008 7:30 pm
by BMAONE23
Perhaps it isn't square at all but only appears to be so from our viewpoint. It could likely be conical like SN_1987A. As seen in this APOD http://antwrp.gsfc.nasa.gov/apod/ap990209.html maybe we are viewing a conical SN from, per chance alignment, its exact side view.

Re: The Red Square Nebula

Posted: Wed May 28, 2008 5:21 pm
by Arramon
jesusfreak16 wrote:Does anybody have any ideas on how the Red Square Nebula(MWC 922) got its almost right angle corners?

http://antwrp.gsfc.nasa.gov/apod/ap070416.html

How did it originate?I believe it was made by intelligent design,but that's my belief.I'm not trying to make a big deal about this,but I think it would be interesting to see how others believe this nebula got its shape.
(In other words,I'm not trying to cause any debate,but merely to see other people's ideas.)
here we go... scientists and astrophysicists take your mark, get set!.....................GO!