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NASA’s Webb takes star-filled portrait of Pillars of Creation

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Re: NASA’s Webb takes star-filled portrait of Pillars of Creation

#51

Post by peanutz454 »

nuccy wrote: post #28
technonerd wrote: post #27

Earlier quoted context omitted.

Handy Dandy Slider action between the two! https://esawebb.org/images/comparisons/weic2216/

Technically the comparison is not totally fair, that Hubble image was taken in visible light, while Webb's in infrared. Dust blocks visible light stronger, so background stars are effectively hidden from Hubble, but not from Webb. Here [1] you can see same field in visible and close infrared taken by Hubble. Webb of course shines in all the fine details and faint stars number. [1] https://cdn.spacetelescope.org/archi…

Now I am intrigued, the infrared image from Hubble seems to be able to see through even more clouds than JWST! What gives?

Re: NASA’s Webb takes star-filled portrait of Pillars of Creation

#52

Post by pkaye »

xracy wrote: post #25

Is there some limit on the number of pictures the Webb Telescope can take in a day? Every time I see a picture from it, I just want more.

There is a 68GB capacity SSD which limits how much data it can store and it can transmit 28GB to earth per 24 hours. It operation is batch operation. Job files are queued up to operate at specific times.

Re: NASA’s Webb takes star-filled portrait of Pillars of Creation

#53

Post by dirtyid »

zimpenfish wrote: post #30
dirtyid wrote: post #22

Wild picture, but less sublime than the original. Same feels when NASA/ESA deconstructed the gas layers in 3d to refect the thin layers (like old school parallax animation background) instead of the awesome awesome voluminous celestia architecture I had in my head. Some old shows look worse in HD. https://www.nasa.gov/image-feature/goddard/pillars-of-creati...

I do kinda get a bit more "oomph" from the old picture because it feels like it's been punched out of space rather than being a wispy thing in the way (e.g. you can see more stars through it.) Which is bonkers because the new photo is amazing .

>"oomph"

Yeah, I think James Webb (being amazing) and resolving so much more stars in these photos kind of removes the oomph of original Hubble photos that showed seemingly lonely cosmic monoliths in largely empty void Which made the subject feel more sublime. New photos have so much stars which everywhere, shifts the enormity of structures onto the sheer abundance of the background universe. It makes the subject feel smaller by revealing just how much bigger the cosmos is. Amazing in a different way.

Re: NASA’s Webb takes star-filled portrait of Pillars of Creation

#54

Post by peanutz454 »

mwidell wrote: post #41

James Webb telescope is great and all, but I have to say I think the older image is more stunning and more aesthetically pleasing. Cleaner, simpler, nicer colors, more mysterious looking.

I agree with this, and I hope a simple comparison of photos from the two telescopes does not capture headlines anymore. I hope the next story to hit the top is one about something new we learned due to JWST, which I am sure is already happening but maybe not grabbing our attention the same way.

Re: NASA’s Webb takes star-filled portrait of Pillars of Creation

#55

Post by jwuphysics »

etrautmann wrote: post #50
ajkjk wrote: post #48

Would it be possible for them to algorithmically remove the lens artifacts? I suppose just "anything with hexagonal symmetry gets deleted". They're kinda pretty but it's sad to think that this isn't what it would actually look like if you had really good infrared eyes.

Interesting- If you look closely at the super bright objects, there are both hexagonally symmetric artifacts and cardinal up/down/left/right artifacts. I’d love to hear from someone with knowledge of how these arise and what optical tradeoffs prevent designs from eliminating them.

It's possible through deconvolution with a model of the "point spread function" aka PSF. There are techniques from radio astronomy (where interferometry necessitates some kind of Fourier basis model and deconvolution/imaging procedure) which has been extended to the optical domain.

See for example: https://twitter.com/NGC3314/status/1582442367482634242?t=Eaa...

Re: NASA’s Webb takes star-filled portrait of Pillars of Creation

#56

Post by lgl »

etrautmann wrote: post #50
ajkjk wrote: post #48

Would it be possible for them to algorithmically remove the lens artifacts? I suppose just "anything with hexagonal symmetry gets deleted". They're kinda pretty but it's sad to think that this isn't what it would actually look like if you had really good infrared eyes.

Interesting- If you look closely at the super bright objects, there are both hexagonally symmetric artifacts and cardinal up/down/left/right artifacts. I’d love to hear from someone with knowledge of how these arise and what optical tradeoffs prevent designs from eliminating them.

You can read about their formation on several publications. For instance: https://bigthink.com/starts-with-a-bang/james-webb-spikes/

Re: NASA’s Webb takes star-filled portrait of Pillars of Creation

#57

Post by CamperBob2 »

anjc wrote: post #47

Why are so many low magnitude stars in this image, not shrouded by gas, not visible at all in the previous image? Surely some visible light must be emitted by these?

If they are red-shifted enough, Hubble wouldn't have seen them at all.

Keep in mind that while the X and Y axes in this shot are only a few light years across, the Z axis is potentially 13 billion light years deep.

Re: NASA’s Webb takes star-filled portrait of Pillars of Creation

#59

Post by Laremere »

etrautmann wrote: post #50
ajkjk wrote: post #48

Would it be possible for them to algorithmically remove the lens artifacts? I suppose just "anything with hexagonal symmetry gets deleted". They're kinda pretty but it's sad to think that this isn't what it would actually look like if you had really good infrared eyes.

Interesting- If you look closely at the super bright objects, there are both hexagonally symmetric artifacts and cardinal up/down/left/right artifacts. I’d love to hear from someone with knowledge of how these arise and what optical tradeoffs prevent designs from eliminating them.

There are 2 causes of diffraction spikes:

1. The hexagonal mirrors. Trade off is larger mirrors, and the ability to fold the telescope. 2. The struts holding the secondary mirror. Basically can't get rid of this without a very different telescope design.

Causes of both are the best design for getting a lot of light into a space telescope's sensors. In practice has less impact on the science than you might think. The diffraction spikes are much fainter than the main image. It's only bright foreground stars - which the James Webb isn't trying to image anyways - that cause visible spikes.

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