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James Webb first images – complete set of high resolution shots now live

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Re: James Webb first images – complete set of high resolution shots now live

#311

Post by ehsankia »

jvanderbot wrote: post #304
sbierwagen wrote: post #292

Earlier quoted context omitted.

NGC3372 is inside our galaxy, just 8500 light years away. It's not redshifted by metric expansion to any appreciable degree, (A calculator I just checked gave me a z of 0.000000617) and radial velocity is a sedate ~34 km/s. (z = 0.000000115) The redshift on the other JWST images is because most of them are of objects that are much, much, much farther away. Infrared telescopes are great for observing those, but that's…

Maybe my question would be better asked for other objects images then, but I can just google how far things are redshifted at extreme distances as well.

My understanding is that the IR here is used to see "through" the "smoke", so you can see more details that would normally be obstructed.

A good way to see this is comparing it to Hubble [1], a lot of the extra detail you see is thanks to IR letting you see the stars behind.

[1] https://johnedchristensen.github.io/WebbCompare/

Re: James Webb first images – complete set of high resolution shots now live

#312

Post by joshuahedlund »

mike10921 wrote: post #68
ceejayoz wrote: post #56

Earlier quoted context omitted.

The difference is in a) the details and b) the length of time the telescope has to gather light to get the photo. JWST got the photo in hours when Hubble took weeks, and there's easily 10x as many objects in the JWST shot. JWST can thus observe much fainter and much more distant objects - galaxies billions of years old, exoplanets, etc., and it can do more of it .

Of course, I get it, but we are allowed to admit that to the average person so far it looks like more of the same.

Yes, we can admit it for some of the images, like the first one (crisper details and new galaxies notwithstanding). Some of them are pretty stunning in the improvement, though, IMO:

- Carina Nebulae: https://old.reddit.com/r/space/comments/vxengq/carina_nebula...

- Southern Ring Nebulae: https://old.reddit.com/r/space/comments/vxfdva/hastily_throw...

The new ones make the old ones look blurry and dull!

Re: James Webb first images – complete set of high resolution shots now live

#313

Post by ehsankia »

quaintdev wrote: post #48
crhulls wrote: post #15

Here is a Hubble side by side of the deep field for comparison https://www.facebook.com/photo.php?fbid=10159217085846758&se...

A GIF comparing both Hubble and JWST https://i.redd.it/9uyhwijeo0b91.gif

Here's another tool with all 4 photos:

https://johnedchristensen.github.io/WebbCompare/

Re: James Webb first images – complete set of high resolution shots now live

#314

Post by ehsankia »

oittaa wrote: post #96

Unfortunately the NASA stream online was a disaster. Choppy video and it seemed like nobody had prepared anything. Also 720p in 2022... Don't get me wrong, the images are amazing, but when small startups like Rocket Lab can have uninterrupted streams all the way to the orbit, but NASA stream from a studio looks more amateurish than your average 13-year-old Fortnite player on Twitch, it leaves a pretty bad impression.

Seriously it was such a mess. Lag aside, they had MULTIPLE cases of either someone's mic not being on, or someone with a hot mic after they were done whispering over the stream. Almost every single transition to scientists in other cities failed. This is really unfortunate because they hyped up this event big time. They announced it two weeks in advance, had a countdown, even had scientists do "reaction" videos to seeing the photos for the first time...

People often underestimate how insanely hard it is to put something like this together, but I'm surprised NASA did, It's not like it's the first time NASA does a livecast.

Re: James Webb first images – complete set of high resolution shots now live

#315

Post by s1artibartfast »

mensetmanusman wrote: post #294
whiteboardr wrote: post #137

Earlier quoted context omitted.

Thanks, but how is the sausage made then? Guess, that’s my main question. I get that the aquired data needs to be transformed in a way so we get an image that depicts a reality we can visually process. I honestly thought there’s some tools in Nasa’s imaging group that, based on scientific rules, pumps out an image that is correct - seeing Photoshop in use left me wonder… I get that the investment needs to be “sold” t…

Because light red shifts over time/expansion, you could color these towards blue until they cover parts of the human vision space to what they would look like on earth a billion years ago or so. In that case you could render the image differently depending on how many millions of years in the past you were interested in. I.e these used to be human “visible” on earth, but eventually their colors shifted beyond what we…

Many of these images are close and not redshifted.

Re: James Webb first images – complete set of high resolution shots now live

#316

Post by adonovan »

NeutralForest wrote: post #258

Absolutely breathtaking that such a tiny window inside the universe would cover so much.

It always blows my mind that when you look at the night sky, aside from 7 planets and only 2 galaxies, every point of light you see is a star; but when these space telescopes point at a patch of nothingness, we see a starry night where every point of light is a (freaking) galaxy.

Re: James Webb first images – complete set of high resolution shots now live

#317

Post by s1artibartfast »

TheOtherHobbes wrote: post #276
april_22 wrote: post #184

Earlier quoted context omitted.

Which makes me wonder how all these galaxies and nebulas would look like in real life. Would they look similar to how they colored it? Are those images maybe potraying a completely wrong reality?

There is no "in real life." The size, sensitivity, and spectral response of human eyes is a response to the radiation conditions on Earth, as enhanced by evolution. If the Sun had been redder or bluer and your eyes were the size of your head or much smaller, everything would look very different. The Webb images are infrared so "in real life" you'd never see them as shown here. You'd see whatever was visible in optica…

You are obviously missing the point. They want to know what it would look like to a human observer.

Re: James Webb first images – complete set of high resolution shots now live

#319

Post by pavon »

throwaway5752 wrote: post #27
crhulls wrote: post #15

Here is a Hubble side by side of the deep field for comparison https://www.facebook.com/photo.php?fbid=10159217085846758&se...

My understanding is that it is also 12-13 hours of exposure for the Webb image vs weeks for Hubble.

That is incorrect. The famous Hubble Ultra Deep Field image[1] took 11.3 days of imaging spread over four months (because of high demand to use Hubble). However, that is a different part of the sky. The Hubble image shown here was taken as part of RELICS[2], a survey of images to find good candidates for JWST to image, and was only exposed for 1.7 hours (5 orbits at ~20 minutes each), compared to JWST's exposure time of 12.5 hours. So comparisons between between Hubble and JWST for that particular shot are not fair to Hubble.

[1]https://esahubble.org/images/heic0611b/

[2]https://archive.stsci.edu/prepds/relics/

Re: James Webb first images – complete set of high resolution shots now live

#320

Post by vanattab »

DougBTX wrote: post #302
The5thElephant wrote: post #260

Earlier quoted context omitted.

It's all real, but you would not be able to see it with your bare eyes even if you were relatively close to the nebula. The world around us would look very different if our eyes could perceive more of the infrared and ultraviolet spectrum. The coloring is usually done to indicate different temperatures or wavelengths detected, so it can be a bit misleading.

Maybe a similar but different question then, but what would a photo on Earth look like with this filter?

The color mapping of these images is not the same as the what is used for JWST but this will probably give you some clue.

https://images.app.goo.gl/9gqtdbcsBxY6RonY9 https://images.app.goo.gl/pG7sfjLGU9nqmAvH7 https://images.app.goo.gl/JGebDZ7V5EamKoY89

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