Download James Webb Images PATCHED
Keiko Bludworth
Uranus is not the first planet that comes to astronomers' minds when they hear about rings; its more spectacular celestial cousins like Saturn and Jupiter earn that distinction. Yet the rings around Uranus are quite magnificent on their own, as revealed among other things by recent images taken by NASA's James Webb Space Telescope (JWST).
The images, which were captured by the JWST's NIRCam (Near-Infrared Camera), are particularly notable for the clarity and detail that they offer in showing the rings of Uranus. Among these is the famous zeta ring, a very faint and dusty celestial object first discovered by the Voyager 2 satellite in 1986. On its website NASA describes this ring as "elusive" and adds that the JWST was only able to capture an image of "the extremely faint and diffuse ring closest to the planet" because of its "exquisite sensitivity."
The rings of Uranus are certainly not alone as far as standout images from JWST are concerned. While the Voyager 2 images of Uranus shows a cyan ball, the new JWST images show a number of hues: Electric bright white, soft purple, light blue and dark blue. The JWST also caught images of many of the 27 moons that orbit Uranus and sport Shakespearean names: Belinda, Bianca, Cressida, Desdemona, Juliet, Perdita, Portia, Puck and Rosalind.
NASA scientists also pointed out that the new images reveal tumult beneath the seemingly placid Uranusian surface. They note that there are several bright storms visible both near and below the southern border of the polar cap. It's a good thing we got this image, because there are no NASA missions officially planned to the distant planet, though one may launch between 2028 and 2038.
That's how a team of scientists, writers and educators described in vivid detail just one of the breathtaking celestial images captured by the James Webb Space Telescope so people with visual impairments could appreciate it, too.
The $10 billion James Webb Space Telescope, under development for decades and launched into space in December, is NASA's newest and most powerful. On July 12, the first color images were released. And scientists have been poring over the data that's come coming from the telescope.
"We know these galaxies pretty well, but seeing these images with James Webb, it's like putting glasses on," Lotz told NPR. "Like, things we couldn't see before now are just crystal clear. And it's been overwhelming. It's been really overwhelming."
Downloads from STSCI were not possible until I set my Firefox browser to welcome all popups, not just those from mast.stsci. The people at MAST/STSCI were very helpful, and I am able to obtain images.
You probably guessed by now that I am hoping this thread will develop as a place to start for those who want to process James Webb images. So I present one problem now, and I will pose others later as needed.
I've set up a computer just to process MAST files and have processed the 6 NIRCAM filter images of SMACS 0723 as a test of process. See Joe DePasquale's drop box at _1pDa?dl=0 for how to combine the filters and use his pixinsight script to eliminate the blown out bright star cores. Also, look at the youtube channel for Launch Pad Astronomy featuring JWST processing. My result is too big to post, but I was happy with it. There is a lot of Jupyter notebook tutorials for processing and analyzing these data
An important feature of Pagan's method is that she may combine images from more than three filters. I think she mentioned that she had used six or eight. This seems an useful way to make finer discriminations regarding temperatures and elements in gas clouds.
Stephen's Quintet is definitely not the first image you want to create. It's a mosaic of over 1800 nircam images and 6 MIRI images. I searched MAST for the files and attached is a screen shot of the nircam overlays.
It was my understanding that the blue and orange frames represented all available views (images). I have been downloading single files, one for each filter, which range from 80 to 600+ MB. They may well be composites, but they otherwise look normal. That is, they look complete, not like parts of a mosaic.
I will try again to select and attach an example, which is only a screen shot of one quadrant of the original, which I suspect would be too big to include. But I don't see a way to select anything. The "Image" box asks for a URL, but I don't have a server for these images. The "My Media" button has a dialog that indicates it gets media that has been uploaded to a community website. I haven't found a place to upload. The help menu shows a nice little icon for inserting an image, but I don't see the icon on this page, just little boxes with function labels.
But perhaps you are right that Stephan's Quintet is too big a bite. But every choice seems to come with its own special problem. The Cartwheel images were somewhat gauzy and lacking nice stars for alignment and registration. The M74 stars were in amongst the dust and also hard to align. Stephan's Quintet was easy to align, but two of the three filter images that I downloaded contained a lot of banding. After several successful downloads, I now find that downloads from MAST are failing just before completion of the .part file. So perhaps I will grab those Pasquale .tiff files and see what I can learn from them.
No, I'm just trying to put together three JWST filter images into one file aligned and combined with color. I have image selection on MAST, downloading, and registration somewhat under control, but I don't really understand yet how one gets from three monochrome images to one color image. I never worried about that with my DSLR. I will worry about noise, balance, masking, enhancements, and the kitchen sink later. One can hardly underestimate my astroimaging skills.
Are you using Pixinsight? If so, do a linear fit with the three filters, use color combine to create the color and finally do photometric color correction (PCC). There are other steps you can do to clean the monochrome images, but those are the simplest steps for producing a reasonably good RGB. Also, assign the filters from lowest to highest -> R, G, B, respectively.
I made an interesting discovery about the banded MAST images of Stephan's Quintet. I was having problems with downloads getting close to completion and then stopping, so I tried a new download of the f444w image using the Curl shell script, which is one alternative to ZIP. Once the shell script downloads, you just open the terminal program, write "bash" at the prompt, and drop the .sh file onto the terminal window. The image downloaded without problem and I dropped it into Pixinsight, where it failed to load, giving error messages and complaining about the "legacy" fits format. This had not happened with previous downloads. So I dropped it into FITZ Liberator and saved it as a .tiff file without further processing. Then I dropped the tiff file into Pixinsight and gave it a little stretch. This time the image was crystal clear, no banding! This is the same MAST file that I had previously downloaded. Here is a screen shot comparing the ZIP and Curl downloads, ZIP on the left.
But what do the images actually show? Royal Observatory Greenwich astronomer Dr Greg Brown gives us the lowdown on the first Webb images, and explains how the new space telescope could take us even deeper into the universe...
Beautiful images are not all the Webb is going to be producing, and while they may not seem as immediately impressive, these other data products have the potential to be even more impactful than the most stunning of pictures.
Awe. Pure awe. There is just so much detail in this image that we have never seen before. As someone who is lucky enough to think about how galaxies form and evolve every day, they continue to surprise me. These images are just stunningly beautiful.
The second is related to those stretched out and strangely shaped galaxies. The reason they are stretched out is due to the gravitational lensing effect I mentioned earlier. The very far away galaxies, that are behind the more nearby galaxy cluster, have their light distorted by the fact that the cluster is bending spacetime. You can also actually see multiple images of some of the galaxies. The thing that stands out about this lens is how sharp and thin some of those features are! That will allow us to make an even better model of where the mass is and will help us study the details of the very distant galaxies better than ever.
df19127ead