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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

#6

Post by Azrael3000 »

arriu wrote: post #5

I love that there is a star showing some drift

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)

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

#7

Post by nabla9 »

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.

(If I remember correctly JWST took this image in less than 12 hours, Hubble stared at it for much longer. Correct me if I'm wrong).

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

#8

Post by atoav »

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.

JWST shows a much bigger part of the wavelength spectrum. That means it can image things that would just not show up in Hubble.

E.g. think about far away galaxies that have been redshifted so much (due to the expanding universe) that they fell below the lower wavelength threshold of Hubble.

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

#9

Post by outputchannel »

Azrael3000 wrote: post #6
arriu wrote: post #5

I love that there is a star showing some drift

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 the two frames, there seems to be a noticeable shift in position that doesn't occur with other objects.

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

#10

Post by gliptic »

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…

Yeap, this is very likely proper motion. That star is in our galaxy.
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