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Show HN: A JWST/Hubble deepfield comparison on a zoomable/pannable map interface

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Re: Show HN: A JWST/Hubble deepfield comparison on a zoomable/pannable map interface

#21

Post by Cthulhu_ »

hrnnnnnn wrote: post #19
Synaesthesia wrote: post #17

This isn't a real image of an exoplanet right? The one in the background. Nowhere does it say that, which I think is beyond the ability of even JWST, to resolve an exoplanet at 50 light years? https://www.nasa.gov/image-feature/goddard/2022/nasa-s-webb-...

The image in the background is an artist's rendition. The graph is the real image. Exoplanets are too far away and too small to image directly.

I do hope they can train the JWST at a close-by star and at least see a dot that represents an exoplanet.

Re: Show HN: A JWST/Hubble deepfield comparison on a zoomable/pannable map interface

#22

Post by 0x_rs »

nabla9 wrote: post #7

JWST and Hubble have roughly similar angular resolution. Hubble marginally better. JWST needs larger mirror for the same angular resolution because it uses longer wavelengths. Hubble: 0.04 arcsec at 500 nm JWST: 0.068 arcsec at 2 μm The difference is in wavelengths, image quality, and light collecting ability (size of the mirror). Hubble has to stare longer into a same spot to collect the same amount of light as JWST…

Hubble's composite of SMACS took 5 orbits, which ends up being about a couple hours maximum. Most websites talked about the deep fields such as XDF (hundreds of orbits) while showing the comparison between the RELICS and JWST pictures, which I believe was very misleading from how this is repeated. Not to detract from its capabilities, of course.

Re: Show HN: A JWST/Hubble deepfield comparison on a zoomable/pannable map interface

#23

Post by shmageggy »

outputchannel wrote: post #9
Azrael3000 wrote: post #6

Earlier quoted context omitted.

There's no drifting there. What you are seeing is gravitational lensing. The light of (most likely a galaxy) is bent around another galaxy or star which distorts its appearance. Also this means it can potentially show up multiple times on the image (e.g. opposite side w.r.t. the lensing object)

Thanks for the comments! It does look like some stars may be exhibiting stellar drift, I've isolated an example here: https://academo.org/demos/james-webb-vs-hubble-telescope-com... This is from the middle-right side of the deep field. If you look slightly below the two central galaxies, there is what looks to be a foreground star (I say that due to its brightness and the fact it has a starburst effect) and between t…

I was wondering how you made that gif and looking for an option on the UI to automatically export one, but then I realized you are OP. That would be a cool feature to add.

Re: Show HN: A JWST/Hubble deepfield comparison on a zoomable/pannable map interface

#24

Post by privong »

hrnnnnnn wrote: post #19
Synaesthesia wrote: post #17

This isn't a real image of an exoplanet right? The one in the background. Nowhere does it say that, which I think is beyond the ability of even JWST, to resolve an exoplanet at 50 light years? https://www.nasa.gov/image-feature/goddard/2022/nasa-s-webb-...

The image in the background is an artist's rendition. The graph is the real image. Exoplanets are too far away and too small to image directly.

> Exoplanets are too far away and too small to image directly.

If you mean resolving details of the exoplanet, then yes that is currently true. But we have imaged exoplanets directly, meaning taken an image of a star where one can also see the planet directly in the image. [0] has a list of directly imaged exoplanets.

[0] https://en.wikipedia.org/wiki/List_of_directly_imaged_exopla...

Re: Show HN: A JWST/Hubble deepfield comparison on a zoomable/pannable map interface

#26

Post by gliptic »

sph wrote: post #11
nabla9 wrote: post #7

JWST and Hubble have roughly similar angular resolution. Hubble marginally better. JWST needs larger mirror for the same angular resolution because it uses longer wavelengths. Hubble: 0.04 arcsec at 500 nm JWST: 0.068 arcsec at 2 μm The difference is in wavelengths, image quality, and light collecting ability (size of the mirror). Hubble has to stare longer into a same spot to collect the same amount of light as JWST…

Would JWST have made a more detailed picture if it had stared on that spot as long as Hubble did?

Resolution would not improve, but contrast would and you would be able to see fainter objects with less noise.

Re: Show HN: A JWST/Hubble deepfield comparison on a zoomable/pannable map interface

#27

Post by falseprofit »

holoduke wrote: post #18

Would there be a moment we cannot zoom in further because we hit the event horizon with the jwst? Or are there still hidden galaxies behind what we can see with the jwst?

The furthest back potentially visible stuff before the dark age won’t be galaxies, which formed after the first stars. We still have never seen a first generation star, and I’d be surprised if Webb could.

Re: Show HN: A JWST/Hubble deepfield comparison on a zoomable/pannable map interface

#28

Post by falseprofit »

Synaesthesia wrote: post #14
fvold wrote: post #12

I want to see a comparison of the infrared from Hubble vs the infrared from James. I also want to normalize calling JWST just "James" :)

The Hubble only went into very near infrared, nothing like JWST. Also JWST is a million miles from earth so it is ultra cold. I like "James Webb Science Telescope" for JWST.

Just Wonderful Space Telescope

Re: Show HN: A JWST/Hubble deepfield comparison on a zoomable/pannable map interface

#29

Post by falseprofit »

revskill wrote: post #4

These are annoying to me because lacks of real difference from a senior astronaut viewpoint. As a normal user, the only difference i could see is just "brighter", anything more to add to the details ? Else i could say, just the same.

Check out some of the reddest galaxies in the Webb image. Even the big ones are entirely invisible on the Hubble image.

Re: Show HN: A JWST/Hubble deepfield comparison on a zoomable/pannable map interface

#30

Post by hrnnnnnn »

privong wrote: post #24
hrnnnnnn wrote: post #19

Earlier quoted context omitted.

The image in the background is an artist's rendition. The graph is the real image. Exoplanets are too far away and too small to image directly.

> Exoplanets are too far away and too small to image directly. If you mean resolving details of the exoplanet, then yes that is currently true. But we have imaged exoplanets directly, meaning taken an image of a star where one can also see the planet directly in the image. [0] has a list of directly imaged exoplanets. [0] https://en.wikipedia.org/wiki/List_of_directly_imaged_exopla...

Woah didn't know about that. The gif on that page is incredible!
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