James Webb Space Telescope News

[Chomiq]

These look better:

NASA’s Webb Captures Dying Star’s Final ‘Performance’ in Fine Detail

webbtelescope.org

NASA’s Webb Reveals Cosmic Cliffs, Glittering Landscape of Star Birth

webbtelescope.org

https://webbtelescope.org/contents/news-releases/2022/news-2022-034

 

[Bomby569]

I am very familiar with gravitational lensing. However if you look closely, there are areas of the image where distorsions are taking place but not where they should be and not where there is an apparent source.

i think you are looking into deep space, there are countless sources of gravity until the light reaches us, some you can't even see, not everything emits a light.

 

[Frick]

I am very familiar with gravitational lensing. However if you look closely, there are areas of the image where distorsions are taking place but not where they should be and not where there is an apparent source.

You know gravitational lensing so well you can look at that picture and confidently say "that's not it"? In any case any kinks are worked on. And remember that is a composite image, basically made for the public.

Anyway:

 

[Wirko]

I am very familiar with gravitational lensing. However if you look closely, there are areas of the image where distorsions are taking place but not where they should be and not where there is an apparent source.

Distorted object overlap other stars (or other types of point-like objects) that are undistorted. Aberrations can't explain that.

 

[Bomby569]

i especially liked this picture, the starts in this "dance" as NASA put it. Incredible

 

[Lew Zealand]

Apart from that, the only distortion I see are the spikes. I'm wondering if they can reduce them in software.

The (diffraction) spikes are from the segmented mirrors, there is no way around them and they look like multiple overlapping spikes because there are multiple mirrors. Hubble's spikes are from the X-shaped secondary mirror support up front, but Webb uses a different design. No purpose is served from eliminating them in software as that just further degrades the data in the image. The spikes are there on each and every light source in the image but they're far too faint to see or register in the fainter light sources but there are actual galaxies in that image which are bright enough to make their diffraction spikes visible, which is crazy. Usually you only get spikes from nearby stars.

The spikes also aren't simple white lines, they contain some kind of colourful diffraction patterns. It's possible that the scientists can extract some useful information regarding the spectrum of light.

Also, this is infrared, so it's false colour. Do we know what wavelengths was this image taken in?

Yes, definitely false color but pretty much every picture of the night sky which is taken of a galaxy or anything other than a Solar System object uses false color. >99% of them. For instance, all those wonderful Hubble images are false color with different specific wavelengths mapped to B, G, and R, usually Oxygen III, Hydrogen Alpha, and then something else of interest, usually Sulfur II, respectively.

 

[mclaren85]

And here is the untouched (raw) version:

Raw photo

 

[birdie]

Inside the Universe Machine: The Webb Space Telescope’s Ultra-Reliable Radio

Any scientific data the JWST collects during its lifetime will need to be stored on board, because the spacecraft doesn’t maintain round-the-clock contact with Earth. The on-board storage is enough to collect data for about 24 hours before it runs out of room.

spectrum.ieee.org

 

[Chomiq]

Hubble vs Webb:

https://i.redd.it/9uyhwijeo0b91.gif

 

[ExcuseMeWtf]

I assume those six lines from each light source (due to Webb's mirror pattern if someone didn't know) are pretty easy to compensate for in image processing?

 

[Bomby569]

Hubble vs Webb:

https://i.redd.it/9uyhwijeo0b91.gif

when you finally get the money to leave 540p and get a 4k monitor

 

[ExcuseMeWtf]

Awesome video to see how people actually knowledgeable in this stuff react to the pics and what can they tell from them.

 

[Lew Zealand]

I assume those six lines from each light source (due to Webb's mirror pattern if someone didn't know) are pretty easy to compensate for in image processing?

If someone was interested in making a pretty pic without those diffraction spikes in them, there are techniques for reducing them but not for scientific purposes, and TBF science is the $10B job for Webb. Reducing those could compromise the other data in the image so you just work around them for science purposes.

If there is going to be an excessively bright star (lol or galaxy with the Webb!), you try to keep it out of the frame or make sure the scope is positioned where the diffraction spikes are in another part of your image and not overlapping your specific area of interest. The Hubble has 4 spikes where Webb has 6 (different designs), so that might be a slightly bigger annoyance with Webb.

 

[the54thvoid]

^^ Yeah, the telescope wasn't built for pretty pictures. NASA releases these to give us some 'wow' factor and I'm glad they do it to service public expectations.

I tip my hat to NASA. I know there are global components in Webb but it is NASA that brings it all together. I think its the greatest thing the US has given to the scientific world.

 

[ExcuseMeWtf]

If someone was interested in making a pretty pic without those diffraction spikes in them, there are techniques for reducing them but not for scientific purposes, and TBF science is the $10B job for Webb. Reducing those could compromise the other data in the image so you just work around them for science purposes.

If there is going to be an excessively bright star (lol or galaxy with the Webb!), you try to keep it out of the frame or make sure the scope is positioned where the diffraction spikes are in another part of your image and not overlapping your specific area of interest. The Hubble has 4 spikes where Webb has 6 (different designs), so that might be a slightly bigger annoyance with Webb.

No idea where you got the idea "it was just for the pretty pic" but okay.

It's pretty clear anyone with Photoshop could do that if that were the case.

Please don't make assumptions about others' intents and get condescending just because of that. It's rude.

 

[the54thvoid]

I doubt that was the assumption, and I'm posting this to suggest we avoid bickering over semantics.

Let the science continue...

 

[Braegnok]

iPhone 12 & countertop.

 

[rethcirE]

 

[Bomby569]

i think for what i've read the higher resolution is not for higher quality pics, that's a fortunate side effect, the main objective is to get a more accurate picture of the light spectrum for stuff like analysis of element composition.

 

[lexluthermiester]

Seems NASA may think this is 'gravitational lensing'.

Last Updated: 12th July, 2022 18:37 IST
James Webb Space Telescope's Image Distortion Explained; What Is Gravitational Lensing?

That statement is preliminary. They don't actually know what is causing the distortions. The reason for this is that the distortions are not symmetrical. Gravitational lensing is always symmetrical around the source of the gravity-well. The distortions shown in that image are not. Further investigation is required.

Distorted object overlap other stars (or other types of point-like objects) that are undistorted. Aberrations can't explain that.

Neither can gravitational lensing.

 

[Lew Zealand]

That statement is preliminary. They don't actually know what is causing the distortions. The reason for this is that the distortions are not symmetrical. Gravitational lensing is always symmetrical around the source of the gravity-well. The distortions shown in that image are not. Further investigation is required.


Neither can gravitational lensing.

Gravitation lenses are not perfect lenses and are not symmetrical because it's a conglomeration of galaxies, each adding it's gravity to the lens from the particular location it's in. And they are spread out in all 3 dimensions.

There are no symmetrical distortions, other than rare chance, when your 'lens' is an irregular blob.

 

[cvaldes]

For US residents, this coming Wednesday July 13 at 9pm PBS will premiere a NOVA episode "Ultimate Space Telescope" about the James Webb Space Telescope.

Ultimate Space Telescope

Discover how NASA engineers built and launched the most ambitious telescope of all time.

www.pbs.org

I watched this episode last night; it was excellent as I expected.

For those seeking lots of pretty space imagery and celestial eye candy, they will be disappointed.

This NOVA episode told the story of the people who persevered through a 13+ year delay (the JWST was originally scheduled to launch in 2007) and billions of US taxpayer dollars in cost overruns. The program mentioned the original inspiration (the Hubble Deep Field image from 1995) and glossed over the late controversy of the telescope's namesake.

The episode will probably be scheduled for reruns (check your local TV listings) and eventually it should show up in PBS Passport (on-demand streaming archive) for PBS members now that it has been aired. It might also end up on some of the streaming services (AppleTV, Amazon Fire, YouTube+, etc.).

Sorry I have no clue about broadcast schedules or streaming availability for international viewers.

 

[Wirko]

Distorted object overlap other stars (or other types of point-like objects) that are undistorted. Aberrations can't explain that.

Neither can gravitational lensing.

The explanation is simple and very earthly. Some objects are behind the lens, some are in front of it, as viewed from Earth. You see the same effect in other examples of GL, like this one.

Also, the objects that Hubble sees are equally distorted or undistorted compared to what Webb sees:

Hubble vs Webb:

https://i.redd.it/9uyhwijeo0b91.gif

 

[ExcuseMeWtf]

BTW

I assume those six lines from each light source (due to Webb's mirror pattern if someone didn't know) are pretty easy to compensate for in image processing?

Scott Manley answered me here :

 

[lexluthermiester]

Gravitation lenses are not perfect lenses and are not symmetrical because it's a conglomeration of galaxies

That depends on the field of view.

each adding it's gravity to the lens from the particular location it's in.

While true, the image in question does not show anything that can produce lensing.

There are no symmetrical distortions, other than rare chance, when your 'lens' is an irregular blob.

That's utter nonsense.

The explanation is simple and very earthly. Some objects are behind the lens, some are in front of it, as viewed from Earth.

Oh sure, but the effect you suggest is not happening in THAT photo.

You see the same effect in other examples of GL, like this one.

Actually, that photo is a perfect example of how GL is symmetrical.