They are finally coming in and they do not disappoint. The telescope seems to be functioning well, providing crisp, sharp images of the most disant parts of the universe and hence of its earliest times, over 13 billion years ago, i.e. about 700,000 years after the Big Bang.
You can see more of the images here.
The diffraction spikes are distracting
Also the image presents as though many galaxies are swirling around a point slightly to the right of centre. Is that another artefact of the telescope?
file thirteen, you haven’t read anything about those things, have you?
Here: https://petapixel.com/2022/07/11/comparing-hubble-to-james-webb-the-difference-in-detail-is-astounding/
PS
“We now have achieved what’s called ‘diffraction limited alignment’ of the telescope,” said Marshall Perrin, deputy project scientist for Webb at the Space Telescope Science Institute. “The mirrors are focused together as finely as the laws of physics allow, and this is the sharpest image you can get from a telescope of this size.”
file thirteen
Diffraction spikes are an irritant, but they can not be removed without hand editing the data. They are an inescapable product of the properties of light, present in every telescope. Since this photo is a tight zoom on a very distant object, Milky Way stars are to be avoided as much as possible… but that’s more easily said than done.
As for the swirl, no, this is produced by the vast mass of a galaxy cluster between us and the more distant backdrop to that image. Look up Einstein rings for the ultimate expression of that phenomenon.
Diffraction spikes are an irritant, but they can not be removed without hand editing the data.
Given that the absolute size and position of the support rods that cause the diffraction spikes are known, why would they need to be hand-edited away? Could the diffraction spikes not be expected and mathematically factored out? (No, I’m not volunteering to do this)
John, try to resist the urge to make snarky know-nothing replies. If you don’t have anything useful to say, you don’t have to post links to the obvious or quote the irrelevant. Did you really believe I didn’t already know how amazingly accurate the telescope is?
Whoops, italic quote fail
[Fixed it-Mano]
file thirteen,
Given your speculative question as to whether the gravitational lensing (my first response) was an artifact of the telescope, and your irritation at the diffraction spikes (my second), what else should I have concluded?
@file thirteen:
The diffraction spikes are to be expected, but they cannot be removed. The image of a star is the Fourier transform of the part of the primary mirror that isn’t blocked by support struts or a secondary mirror. If you don’t want any diffraction spikes, you need an unobstructed primary mirror. That means that you need to direct the light off-axis to a secondary mirror and on to your instruments. It’s possible, but very expensive and more prone to failure. And even then, the image of a star will not be a point, but simply a different diffraction pattern without spikes (an Airy disk, for example). For JWST, the light will be diffracted into these spikes and counted on the detector, and the hexagonal primary mirror further complicates the diffraction pattern. You could make a model to remove it, but I would consider that to be hand-editing (you would then be showing an image of a model of your data, rather than an image of your data). The spikes can’t be factored out because they show up from a real physical effect in the hardware.
@tbrandt:
The spherical aberration of the Hubble was “a real physical effect in the hardware”, and yet it was factored out by software.
@John:
Why would you think the diffraction spikes caused me irritation? So far, only your comments have caused me irritation.
I did find this article on the JWST diffraction spikes informative.
https://bigthink.com/starts-with-a-bang/james-webb-spikes/