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.
Re: APOD: MWC 922: The Red Square Nebula (2012 Dec 16)
Posted: Sun Dec 16, 2012 6:05 am
by Technogeek Again
Uhm... Given the six-axis radiating lines on many of the other brighter spots in this image -- which look awfully like "lens flare" -- I'd be inclined to suspect that there's something similar going on with the center object, and the shape we're seeing is an artifact.
I presume there are other images which don't have those artifacts but do still show the "square".
Re: APOD: MWC 922: The Red Square Nebula (2012 Dec 16)
http://sixdayscience.wordpress.com/curr ... hapter-15/ wrote:
X marks the spot in the core of the Whirlpool Galaxy! The darkest bar may be the dust ring seen edge-on. The jet seen in wider fields of view is perpendicular to the darkest dust ring. The lighter bar may be another disk seen obliquely. A million solar mass black hole is thought to lurk at the center. Courtesy of Space Telescope Science Institute
Ann
Re: APOD: MWC 922: The Red Square Nebula (2012 Dec 16)
Posted: Sun Dec 16, 2012 7:00 am
by ritwik
and the geometry of space around galaxies is also in 'cone' shape !! Hence when polar regions of galaxy eject materials it fills the space around galaxies and appear as cone shaped filaments !! concept of gravity is RIGHT !!
Re: APOD: MWC 922: The Red Square Nebula (2012 Dec 16)
Posted: Sun Dec 16, 2012 8:52 am
by do_japan
I'm also curious about the 1st poster's observation of hexagonal lens flare on some of the smaller stars. Is there any possibility that lens flare or some other optical effect could be causing the square shape we are seeing?
Re: APOD: MWC 922: The Red Square Nebula (2012 Dec 16)
Posted: Sun Dec 16, 2012 9:00 am
by Jakub Badelek
Technogeek Again wrote:Uhm... Given the six-axis radiating lines on many of the other brighter spots in this image -- which look awfully like "lens flare" -- I'd be inclined to suspect that there's something similar going on with the center object, and the shape we're seeing is an artifact.
I presume there are other images which don't have those artifacts but do still show the "square".
do_japan wrote:I'm also curious about the 1st poster's observation of hexagonal lens flare on some of the smaller stars. Is there any possibility that lens flare or some other optical effect could be causing the square shape we are seeing?
These are most likely diffraction spikes, explained a few times on APOD, or some other optical fenomenon created by telescope.
If it comes to the Square Nebula - what about polarisation? couldn't gas expelled from star be polarised which would cause such geometrical feature?
Re: APOD: MWC 922: The Red Square Nebula (2012 Dec 16)
Posted: Sun Dec 16, 2012 9:05 am
by Boomer12k
Can someone point me in the direction of a NON-infrared, regular visual light picture of this. Thanks. I searched all over the place.
:---[===] *
Re: APOD: MWC 922: The Red Square Nebula (2012 Dec 16)
Re: APOD: MWC 922: The Red Square Nebula (2012 Dec 16)
Posted: Sun Dec 16, 2012 12:13 pm
by Jonn
It's just amazing how so few people in mainstream science connect the obvious dots... This square like every other geometrically correct nebula is just another result of the underlying vacum geometry of spacetime itself.
artie-fact
Posted: Sun Dec 16, 2012 1:34 pm
by neufer
Technogeek Again wrote:
Given the six-axis radiating lines on many of the other brighter spots in this image -- which look awfully like "lens flare" -- I'd be inclined to suspect that there's something similar going on with the center object, and the shape we're seeing is an artifact.
<<The Red Square (Russian: Красная площадь, tr. Krásnaja Plóščaď) is a city square in Moscow, Russia. The square separates the Kremlin, the former royal citadel and currently the official residence of the President of Russia, from a historic merchant quarter known as Kitai-gorod. The Red Square is often considered the central square of Moscow and all of Russia, because Moscow's major streets—which connect to Russia's major highways—originate from the square. The name Red Square comes neither from the colour of the bricks around it (which, in fact, were whitewashed at certain times in history) nor from the link between the colour red and communism. Rather, the name came about because the Russian word красная (krasnaya) can mean either "red" or "beautiful." This word, with the meaning "beautiful", was originally applied to Saint Basil's Cathedral and was subsequently transferred to the nearby square. It is believed that the square acquired its current name (replacing the older Pozhar, or "burnt-out place") in the 17th century. Several ancient Russian towns, such as Suzdal, Yelets, and Pereslavl-Zalessky, have their main square named Krasnaya ploshchad.>>
Re: APOD: MWC 922: The Red Square Nebula (2012 Dec 16)
Posted: Sun Dec 16, 2012 3:10 pm
by Lordcat Darkstar
Reminds me of the old Star Wars arcade game; flying down the trench of the Death Star. . May the force be with you...always.
Re: APOD: MWC 922: The Red Square Nebula (2012 Dec 16)
Re: APOD: MWC 922: The Red Square Nebula (2012 Dec 16)
Posted: Sun Dec 16, 2012 3:32 pm
by Chris Peterson
do_japan wrote:I'm also curious about the 1st poster's observation of hexagonal lens flare on some of the smaller stars. Is there any possibility that lens flare or some other optical effect could be causing the square shape we are seeing?
You are seeing diffraction spikes around a few stars. None of the structure seen in the nebula itself is the product of diffraction or other optical artifacts, however.
Re: APOD: MWC 922: The Red Square Nebula (2012 Dec 16)
Posted: Sun Dec 16, 2012 3:33 pm
by Chris Peterson
ritwik wrote:and the geometry of space around galaxies is also in 'cone' shape !! Hence when polar regions of galaxy eject materials it fills the space around galaxies and appear as cone shaped filaments !! concept of gravity is RIGHT !! :idea:
Unfortunately for this argument, the structure of space around galaxies doesn't have this shape. In three dimensions, the structure of space around mass concentrations is radially symmetrical.
Re: APOD: MWC 922: The Red Square Nebula (2012 Dec 16)
Posted: Sun Dec 16, 2012 4:08 pm
by Technogeek Again
Thanks for the sanity check. I don't follow the discussion very closely, so I'd missed early discussion of the diffraction effect. In fact, I was pretty sure that the square was legit, but given the occasional "are you sure" items I've seen go buy on APOD I felt I needed to ask.
Thanks again, by the way, to everyone who's involved in running this site, all the folks responsible for processing the data into images that are both beautiful and informative (yes, I know it doesn't usually come off the 'scopes that way!), everyone involved in gathering that data (from building the instruments to patiently operating them), to everyone who has contributed to the technologies, and to the knowledge which has gotten us this far, and... basically, thank YOU, everyone. Humanity's done pretty darned well, despite ourselves.
Re: APOD: MWC 922: The Red Square Nebula (2012 Dec 16)
Posted: Sun Dec 16, 2012 4:27 pm
by Zoomer
The way I see this image of MWC 922, and the 1/7/ 2007 APOD of 1987A as well, is that the central object has exploded and collapsed into a small, very dense, rapidly rotating and beam emitting mass. Some factor, possibly the asymmetry of the explosion, has caused the spin axis to mismatch with the beam axis. Therefore when seen from our perspective of MWC 922 directly above the equator of it’s spin, emitted beams would appear as two cones.
The brighter ring seen in 1987A may also be a double. But that was taken when the remnant was very young and it may be that the viewing angle is such that we cannot yet see this until a later time. IF this is true, then it will fit well with what I think is going on in MWC 922.
So, I think the ring(s) in 1987A and the two bright lines in MWC 922 at the extent of the central bright area may be caused by a surge of matter/energy emitted by the jets when a large amount of material ejected in the original nova fell back onto the central object in a bombardment event.
As for the diffraction spikes, yes I see them in the remnant as well as the other bright objects in the image. But they do not line up with either axis (equatorial or spin) of MWC 922, only with each other. And the fact that the image is a composite from two different and widely spaced instruments makes no difference in my opinion.
Re: APOD: MWC 922: The Red Square Nebula (2012 Dec 16)
Posted: Sun Dec 16, 2012 4:48 pm
by Coil_Smoke
It Is a very symmetrical planetary nebula viewed from the side. The ejecta from the central star has formed two cones spreading out from the focus of the star.
Re: APOD: MWC 922: The Red Square Nebula (2012 Dec 16)
Posted: Sun Dec 16, 2012 5:22 pm
by karelvreeburg
As far as I know, this is an hour glass nebula seen from the side, I discussed this alreade with Vincent Icke who agrees, It also looks like a diabolo from the side,. Karel
Re: APOD: MWC 922: The Red Square Nebula (2012 Dec 16)
Posted: Sun Dec 16, 2012 5:25 pm
by Zoomer
Zoomer wrote:The way I see this image of MWC 922, and the 1/7/ 2007 APOD of 1987A as well, is that the central object has exploded and collapsed into a small, very dense, rapidly rotating and beam emitting mass. Some factor, possibly the asymmetry of the explosion, has caused the spin axis to mismatch with the beam axis. Therefore when seen from our perspective of MWC 922 directly above the equator of it’s spin, emitted beams would appear as two cones.
The brighter ring seen in 1987A may also be a double. But that was taken when the remnant was very young and it may be that the viewing angle is such that we cannot yet see this until a later time. IF this is true, then it will fit well with what I think is going on in MWC 922.
So, I think the ring(s) in 1987A and the two bright lines in MWC 922 at the extent of the central bright area may be caused by a surge of matter/energy emitted by the jets when a large amount of material ejected in the original nova fell back onto the central object in a bombardment event.
As for the diffraction spikes, yes I see them in the remnant as well as the other bright objects in the image. But they do not line up with either axis (equatorial or spin) of MWC 922, only with each other. And the fact that the image is a composite from two different and widely spaced instruments makes no difference in my opinion.
In the next to last sentence, instead of "they do not line up with either axis (equatorial or spin) of MWC 922", I should have written "(equatorial or beam)". Sorry.
Re: APOD: MWC 922: The Red Square Nebula (2012 Dec 16)
Posted: Sun Dec 16, 2012 5:29 pm
by Karel Vreeburg
Messier 27 is the same 3-D form but seen from the top, there are many constellations that are in between, but all hour glass or diabolo constellations, No planet forming, it is a star ejecting enormous amounts of material. Suppose the existing planets suffer enormously,… ) Karel
Re: APOD: MWC 922: The Red Square Nebula (2012 Dec 16)
Posted: Sun Dec 16, 2012 5:39 pm
by tmbruner
Henceforth we should call it the Minecraft Nebula.
Re: APOD: MWC 922: The Red Square Nebula (2012 Dec 16)
Posted: Sun Dec 16, 2012 7:57 pm
by LocalColor
Another strange and wonderful image at APOD. Thanks!
Re: APOD: MWC 922: The Red Square Nebula (2012 Dec 16)
Posted: Sun Dec 16, 2012 11:34 pm
by saturno2
A square and the diagonals, too
Re: APOD: MWC 922: The Red Square Nebula (2012 Dec 16)
"A Symmetric Bipolar Nebula around MWC 922"
Peter Tuthill and James Lloyd, 13 April 2007, Science.
<<The startling degree of symmetry and level of intricate linear form make the Red Square nebula around MWC 922 the most symmetrical object of comparable complexity ever imaged. The overall architecture displays a twin opposed conical cavities (known as a bipolar nebula), along the axis of which can be seen a remarkable sequence of sharply defined linear rungs or bars. This series of rungs and conical surfaces lie nested, one within the next, down to the heart of the system, where the hyperbolic bicone surfaces are crossed by a dark lane running across the principle axis.
One particularly fascinating feature visibile in the images is a series of faint radial spokes, like teeth of a comb, pointing away from the center. Structures such as this are rarely seen in nebulae, and the high degree of regularity in this case may point to the intriguing possibility that these bands are shadows cast by periodic ripples or waves on the surface of an inner disk close to the star at the heart of the system.
Keeping in mind this geometry, it is interesting to take a second look at one of the most famous astronomical images of them all: the beautiful and unexpected ring system revealed around the only naked-eye supernova in the last few hundred years - SN1987A. Could the star MWC 922 at the heart of the Red Square one day explode as a supernova, kindling the outer reaches of its nebula into such an incandescent display? We don't know yet for sure, but one thing is certain. The remarkable series of bars seen in the Red Square may make it the best astrophysical laboratory yet discovered for studying the physics of generating the mysterious sharp polar ring systems like that around SN1987A.>>