Explanation: How was the unusual Red Rectangle nebula created? At the nebula's center is an aging binary star system that surely powers the nebula but does not, as yet, explain its colors. The unusual shape of the Red Rectangle is likely due to 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. The unusual colors of the nebula are less well understood, however, and speculation holds that they are partly provided by hydrocarbon molecules that may actually be building blocks for organic life. The Red Rectangle nebula lies about 2,300 light years away towards the constellation of the Unicorn (Monoceros). The nebula is shown above in great detail as recently reprocessed image from Hubble Space Telescope. In a few million years, as one of the central stars becomes further depleted of nuclear fuel, the Red Rectangle nebula will likely bloom into a planetary nebula.
Re: APOD: The Red Rectangle Nebula from Hubble (2013 May 21)
Posted: Tue May 21, 2013 7:36 am
by Boomer12k
Or it could just be MOTHRA!!!!!
"X" marks the spot....or is it the "BlackSpot" from Treasure Island???
You can see some 3d effect if you use your 3d Glasses!!!
Such beauty at the end of a star's life-cycle...such wonders the Universe holds...
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Re: APOD: The Red Rectangle Nebula from Hubble (2013 May 21)
Posted: Tue May 21, 2013 8:52 am
by MargaritaMc
http://apod.nasa.gov/apod/ap040513.html http://apod.nasa.gov/apod/ap100614.html
I find it interesting to compare two earlier Apods of the Red Rectangle with today's re-processed version.
The colour in the 2010 version is more pink-ish than the earlier and later versions. Has anyone any idea why this would be so?
Re: APOD: The Red Rectangle Nebula from Hubble (2013 May 21)
Posted: Tue May 21, 2013 12:31 pm
by geckzilla
MargaritaMc wrote:http://apod.nasa.gov/apod/ap040513.html http://apod.nasa.gov/apod/ap100614.html
I find it interesting to compare two earlier Apods of the Red Rectangle with today's re-processed version.
The colour in the 2010 version is more pink-ish than the earlier and later versions. Has anyone any idea why this would be so?
Because the same data can be given any color balance one prefers. If you took a photo of the sky, you could adjust the color to be warmer or cooler depending on your personal taste. It's the same thing. But depending on how you assign the colors for individual filters it could be easier or more difficult to read the image so even though the colors could be wildly different they are usually presented similarly. You can tell all three versions of the Rectangle were given similar treatment.
Re: APOD: The Red Rectangle Nebula from Hubble (2013 May 21)
Posted: Tue May 21, 2013 12:37 pm
by ArcBird
Sigh... "rectangle" is just because it's viewed from this angle, it is 2 bowl shaped magnetic fields opposite from one another.
Re: APOD: The Red Rectangle Nebula from Hubble (2013 May 21)
Posted: Tue May 21, 2013 12:55 pm
by MargaritaMc
geckzilla wrote:
MargaritaMc wrote:http://apod.nasa.gov/apod/ap040513.html http://apod.nasa.gov/apod/ap100614.html
I find it interesting to compare two earlier Apods of the Red Rectangle with today's re-processed version.
The colour in the 2010 version is more pink-ish than the earlier and later versions. Has anyone any idea why this would be so?
Because the same data can be given any color balance one prefers. If you took a photo of the sky, you could adjust the color to be warmer or cooler depending on your personal taste. It's the same thing. But depending on how you assign the colors for individual filters it could be easier or more difficult to read the image so even though the colors could be wildly different they are usually presented similarly. You can tell all three versions of the Rectangle were given similar treatment.
Thanks, Geckzilla.
I possibly worded my original post poorly, because what I was finding really fascinating was to have each of the the images up in different tabs and flip quickly between them, seeing how the same data had been processed differently. The 2004 image and today's have similar colours, and it intrigued me that the 2010 one was mapped to be slightly pinkish. But this is simply a personal aesthetic choice?
Also, today's Apod is far clearer, sharper. This interests me, especially since watching some videos from Hubble which show something of the possibilities involved in processing. So, you see, I have the frustrating mix of (a) finding astrophotography fascinating and (b) having no personal experience of doing it.
<<Friedrich (Frederick) Engels was born on 28 November 1820 in Barmen, Prussia (now Wuppertal, Germany). At the time, Barmen was an expanding industrial metropole and Frederick was the eldest son of a wealthy German cotton manufacturer. His father, Friederich, Sr., was an evangelical. Accordingly, Engels was raised Christian Pietist. As he grew up, his relationship with his parents became strained because of his atheist beliefs. Parental disapproval of his revolutionary activities is recorded in an October 1848 letter from his mother, Elizabeth Engels. In this letter his mother berates him for having "really gone too far" and "begged" him "to proceed no further.". "You have paid more heed to other people, to strangers, and have taken no account of your mother's pleas. God alone knows what I have felt and suffered of late. I was trembling when I picked up the newspaper and saw therein that a warrant was out for my son's arrest." At the time this letter was written, Frederick Engels was in hiding in Brussels, Belgium, soon to make his way to Switzerland and then, in 1849, back into Germany for participation in the Baden and Palatinate revolutionary uprising. Whilst at Bremen, Engels began reading the philosophy of Hegel, whose teachings had dominated German philosophy at the time. In September 1838, he published his first work, a poem entitled The Bedouin, in the Bremisches Conversationsblatt No. 40.>>
Re: APOD: The Red Rectangle Nebula from Hubble (2013 May 21)
Posted: Tue May 21, 2013 1:31 pm
by geckzilla
MargaritaMc wrote:Also, today's Apod is far clearer, sharper. This interests me, especially since watching some videos from Hubble which show something of the possibilities involved in processing. So, you see, I have the frustrating mix of (a) finding astrophotography fascinating and (b) having no personal experience of doing it.
Re: APOD: The Red Rectangle Nebula from Hubble (2013 May 21)
Posted: Tue May 21, 2013 1:59 pm
by Chris Peterson
geckzilla wrote:
MargaritaMc wrote:Also, today's Apod is far clearer, sharper. This interests me, especially since watching some videos from Hubble which show something of the possibilities involved in processing. So, you see, I have the frustrating mix of (a) finding astrophotography fascinating and (b) having no personal experience of doing it.
Extreme sharpening algorithms are commonly applied to astronomical images- extreme enough to introduce all sorts of image artifacts. This is because aesthetics are not usually the goal, but these techniques can bring out true structure that would not otherwise be visible. So in the case of astronomical images where elucidating structure is important, friends most certainly do encourage friends to use extreme sharpening.
Re: APOD: The Red Rectangle Nebula from Hubble (2013 May 21)
Posted: Tue May 21, 2013 2:02 pm
by Chris Peterson
MargaritaMc wrote:I possibly worded my original post poorly, because what I was finding really fascinating was to have each of the the images up in different tabs and flip quickly between them, seeing how the same data had been processed differently. The 2004 image and today's have similar colours, and it intrigued me that the 2010 one was mapped to be slightly pinkish. But this is simply a personal aesthetic choice?
For the most part, yes. There are an infinite number of ways of mapping the physical data into some sort of color space compatible with our eyes. While any "natural color" scheme will produce broadly similar results (pink = red = magenta), the final mapping is likely to be different for every different processor.
Re: APOD: The Red Rectangle Nebula from Hubble (2013 May 21)
Posted: Tue May 21, 2013 2:15 pm
by geckzilla
Chris Peterson wrote:
geckzilla wrote:
MargaritaMc wrote:Also, today's Apod is far clearer, sharper. This interests me, especially since watching some videos from Hubble which show something of the possibilities involved in processing. So, you see, I have the frustrating mix of (a) finding astrophotography fascinating and (b) having no personal experience of doing it.
Extreme sharpening algorithms are commonly applied to astronomical images- extreme enough to introduce all sorts of image artifacts. This is because aesthetics are not usually the goal, but these techniques can bring out true structure that would not otherwise be visible. So in the case of astronomical images where elucidating structure is important, friends most certainly do encourage friends to use extreme sharpening.
Some structures aren't even there, though... The extreme glows and shadows along edges can make it look like there's a halo of stars, some light, or some shadowy structure where none is present.
Re: APOD: The Red Rectangle Nebula from Hubble (2013 May 21)
Posted: Tue May 21, 2013 2:31 pm
by Chris Peterson
geckzilla wrote:Some structures aren't even there, though... The extreme glows and shadows along edges can make it look like there's a halo of stars, some light, or some shadowy structure where none is present.
True. When the intent is scientific, it is important to understand the nature of artifacts that can be introduced by any particular instrument or processing technique.
Re: APOD: The Red Rectangle Nebula from Hubble (2013 May 21)
Posted: Tue May 21, 2013 2:46 pm
by ta152h0
like the Stinky plant here on Earth, beautiful to look at but, .......why do you smell ? Misterious !
Re: APOD: The Red Rectangle Nebula from Hubble (2013 May 21)
Posted: Tue May 21, 2013 10:54 pm
by Boomer12k
Since this APOD is about processing...this might help....Processing is EVERYTHING....
Especially for me....most of my images are of short duration, I don't have the WEDGE for my scope, and a Field Derotator, and other equipment...so it has to be software supported. The result is not as much light is gathered...so I take more images to stack. I take 16 or so images, make an AVI file, put that in Registax, use that to align, and get the best of each photo into a single end image. Then take it to Photoshop. Using AutoLevel, AutoContrast, AutoColor. I have gotten some better results, a clearer image, and much brighter colors with an almost "back lit" look to them.
The bottom pic, is a little over done. Slightly blurred, but the colors are more vibrant. It was to see what my tablet APP could do...2. is the normal process, and really brought out the detail. 1 is very dingy, and hard to see, but smooth...so in 2 you can see background stars better. The bulges of M27 on both sides are more visible.
So, it depends on what you are after...better detail...more vibrant color...for Aesthetics, or Scientific data...processing can bring it out...So, for todays APOD, the processing is more vibrant than Margarita's second example. Which was probably the picture used for the processing as many features are in both...much sharper too...I am thinking the purpose was to bring out more structural detail.
:---[===] *
Re: APOD: The Red Rectangle Nebula from Hubble (2013 May 21)
Posted: Tue May 21, 2013 11:21 pm
by Ann
Geckzilla wrote:
Some structures aren't even there, though... The extreme glows and shadows along edges can make it look like there's a halo of stars, some light, or some shadowy structure where none is present.
I'm very happy with my software, Guide, and I really like its graphics. Once, however, I found a star which, on magnification, seemed to be surrounded by a multitude of brilliant points. I thought that the star was sitting in a cluster. It wasn't. The diffraction spikes around the star in the photo that must have been involved in producing the graphics had been "translated" by the graphics into a swarm of cluster-like points of light surrounding the star.
I haven't found a similar effect around any other star in Guide, not that I can remember anyway.
Ann
Re: APOD: The Red Rectangle Nebula from Hubble (2013 May 21)
Posted: Wed May 22, 2013 1:49 pm
by Chris Peterson
Ann wrote:I'm very happy with my software, Guide, and I really like its graphics. Once, however, I found a star which, on magnification, seemed to be surrounded by a multitude of brilliant points. I thought that the star was sitting in a cluster. It wasn't. The diffraction spikes around the star in the photo that must have been involved in producing the graphics had been "translated" by the graphics into a swarm of cluster-like points of light surrounding the star.
I haven't found a similar effect around any other star in Guide, not that I can remember anyway.
This effect is found in automatically generated catalogs, with the HST Guide Star catalog being the most prominent. Most bright stars in the GSC are surrounded by false stars generated out of diffraction artifacts. That isn't a problem for its original purpose, since you never guide on bright stars. There is a corrected version of the GSC that has a lot of these artifacts removed, but it's still far from perfect.
Re: APOD: The Red Rectangle Nebula from Hubble (2013 May 21)
Posted: Thu May 23, 2013 1:33 am
by Jake
ArcBird wrote:Sigh... "rectangle" is just because it's viewed from this angle, it is 2 bowl shaped magnetic fields opposite from one another.
The caption already explains the POV aspect, and I don't know where you got the part about magnetic fields.
Re: APOD: The Red Rectangle Nebula from Hubble (2013 May 21)
Posted: Wed May 29, 2013 7:11 pm
by StevenMx
MargaritaMc wrote:
geckzilla wrote:
MargaritaMc wrote:http://apod.nasa.gov/apod/ap040513.html http://apod.nasa.gov/apod/ap100614.html
I find it interesting to compare two earlier Apods of the Red Rectangle with today's re-processed version.
The colour in the 2010 version is more pink-ish than the earlier and later versions. Has anyone any idea why this would be so?
Because the same data can be given any color balance one prefers. If you took a photo of the sky, you could adjust the color to be warmer or cooler depending on your personal taste. It's the same thing. But depending on how you assign the colors for individual filters it could be easier or more difficult to read the image so even though the colors could be wildly different they are usually presented similarly. You can tell all three versions of the Rectangle were given similar treatment.
Thanks, Geckzilla.
I possibly worded my original post poorly, because what I was finding really fascinating was to have each of the the images up in different tabs and flip quickly between them, seeing how the same data had been processed differently. The 2004 image and today's have similar colours, and it intrigued me that the 2010 one was mapped to be slightly pinkish. But this is simply a personal aesthetic choice?
Also, today's Apod is far clearer, sharper. This interests me, especially since watching some videos from Hubble which show something of the possibilities involved in processing. So, you see, I have the frustrating mix of (a) finding astrophotography fascinating and (b) having no personal experience of doing it.
Margarita
Hello Margarita,
Sorry, I haven’t replied sooner, I haven’t been to starship in a few days. Chris Peterson and Geckzilla did a fine job answering your questions about color in image processing. However, I wanted to explain how I derived the Red Rectangle color. If you have ever mined the HLA you will quickly notice that more times than not all the color channels required to make a true-color RGB will not be there. Sometimes there will only be one wavelength. The Red Rectangle only had two small (25Mb) fits files. I used the two channels (with an algorithm) to create a pseudo color for the missing channel. Although this is a false color composited RGB it seems to give pretty good results for human visualization. Once I combine the RGB I neutralize the background then color calibrate the image. I almost never manipulate the individual color channels after this.
Chris Peterson wrote:
geckzilla wrote:
MargaritaMc wrote:Also, today's Apod is far clearer, sharper. This interests me, especially since watching some videos from Hubble which show something of the possibilities involved in processing. So, you see, I have the frustrating mix of (a) finding astrophotography fascinating and (b) having no personal experience of doing it.
Extreme sharpening algorithms are commonly applied to astronomical images- extreme enough to introduce all sorts of image artifacts. This is because aesthetics are not usually the goal, but these techniques can bring out true structure that would not otherwise be visible. So in the case of astronomical images where elucidating structure is important, friends most certainly do encourage friends to use extreme sharpening.
Believe it or not I did not use any “sharpening” techniques on this image. Being the curious type I typically like to lessen brightness gradients in galactic cores and nebulae to see what’s inside. Although natural luminosity is pretty, sometimes you see amazing things under the glare. Here is a link to an example I used on a six panel mosaic of ***Messier 104*** to lessen the galactic core glare. You can see all the way across the galaxy with great detail (no sharpening).
Re: APOD: The Red Rectangle Nebula from Hubble (2013 May 21)
Posted: Wed May 29, 2013 8:13 pm
by MargaritaMc
Thank you very much, indeed, Steven, for taking the time to explain your work on this image. It is always so helpful when the creator of an Apod comes to the board to talk about his image in this way.
As I said in an earlier post on this thread, although I am now deeply interested in how astrophotographical images are created, I have zero practical experience in the subject - I don't even own a proper camera! And as my physical situation of using a wheelchair makes practical astronomy of most kinds rather problematic, I don't see myself being able to gain this practical experience. Therefore, I ask, ask, and ask some more of people, like yourself, who do have this knowledge.
The HLA and fits files and the program called PhotoShop are only beginning to impinge on my awareness and making me think Who knows?? Maybe I don't have to go out and take the photographs myself...?
In the meantime, I looked up the information on Hubble about data relating to this image and so was able to understand what you said about there being only two files/filters. I looked up the image you produced of the Sombrero Galaxy and was fascinated to be able to see the far side! It is a good example of what you wrote about. Thanks for the link.
Best wishes
Margarita
Re: APOD: The Red Rectangle Nebula from Hubble (2013 May 21)
Posted: Wed May 29, 2013 9:17 pm
by Beyond
Yeah, in his brightness lessening of Messier 104, it now looks like a dusty pancake with a small uncooked spot in the center.
So all that brightness comes from that small place in the center?
Re: APOD: The Red Rectangle Nebula from Hubble (2013 May 21)
Posted: Wed May 29, 2013 9:44 pm
by Chris Peterson
Beyond wrote:Yeah, in his brightness lessening of Messier 104, it now looks like a dusty pancake with a small uncooked spot in the center.
So all that brightness comes from that small place in the center?
That's a good example of the sort of compromises you need to make with astronomical images. The dynamic range of the galaxy- the difference in intensity between the brightest and dimmest areas- is several hundred thousand to one. The dynamic range of your computer display is a few hundred to one. That's why galaxies usually look so bright in the center, and it's why galaxies viewed through a telescope often only show the central part. So in this image, the brightness as been very highly compressed into the narrow dynamic range of the output device. The result is an image that totally misrepresents the optical structure, but at the same time allows the entire structure to be seen at once. You can have images optimized for photometry, for structure, for color, and many other things. But whatever you do to emphasize any one particular feature, you probably lose something else.
It's why almost no astronomical image can ever look like something our eyes would actually see.
Re: APOD: The Red Rectangle Nebula from Hubble (2013 May 21)
Posted: Thu May 30, 2013 6:55 pm
by StevenMx
Chris Peterson wrote:
So in this image, the brightness has been very highly compressed into the narrow dynamic range of the output device. The result is an image that totally misrepresents the optical structure, but at the same time allows the entire structure to be seen at once. You can have images optimized for photometry, for structure, for color, and many other things. But whatever you do to emphasize any one particular feature, you probably lose something else.
I did not use dynamic range compression to subdue the galactic core brightness. A DRC of this magnitude would probably distort / destroy data in the rest of the image. Instead multiscale processing on wavelet layers was performed. Furthermore I disagree that my rendition “totally misrepresents” the optical structure of M104 simply by reducing nucleus luminosity. Personally I like the way NASA describes Vicent Peris’s similar rendition of M104 as an “alternative look” at the Sombrero. As an aside, with the glare reduced I don’t see the globular clusters NASA refers to as a possible explanation to Sombreros central bulge even at 11000x resolution.
Chris Peterson wrote:
It's why almost no astronomical image can ever look like something our eyes would actually see.
I don’t think I agree with you here either. I feel very close true-color RGB images can be obtained. Albeit, many wavelengths cannot been seen with our eye or not natural i.e. Ha filters, they do add a certain aesthetic and scientific appeal to astrophotography images.
The Red Rectangle Nebula from Hubble
Who knows?? Maybe I don't have to go out and take the photographs myself...?