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Dr Sardonicus 2022-02-11 20:18

[url=]Star light, star bright, first star I see 18 times tonight...[/url][quote]The James Webb Space Telescope is nearing completion of the first phase of the months-long process of aligning the observatory's primary mirror using the Near Infrared Camera (NIRCam) instrument.

The team's challenge was twofold: confirm that NIRCam was ready to collect light from celestial objects, and then identify starlight from the same star in each of the 18 primary mirror segments. The result is an image mosaic of 18 randomly organized dots of starlight, the product of Webb's unaligned mirror segments all reflecting light from the same star back at Webb's secondary mirror and into NIRCam's detectors.

What looks like a simple image of blurry starlight now becomes the foundation to align and focus the telescope in order for Webb to deliver unprecedented views of the universe this summer. Over the next month or so, the team will gradually adjust the mirror segments until the 18 images become a single star.

"The entire Webb team is ecstatic at how well the first steps of taking images and aligning the telescope are proceeding. We were so happy to see that light makes its way into NIRCam," said Marcia Rieke, principal investigator for the NIRCam instrument and regents professor of astronomy, University of Arizona.

tServo 2022-03-22 12:52

First images from Webb exceed expectations !


jwaltos 2022-03-29 20:00

[QUOTE=tServo;602288]First images from Webb exceed expectations !

(..and Neo's one-liner.)

retina 2022-04-19 11:36

How James Webb's Instruments Work - and What They'll Show Us!

Dr Sardonicus 2022-05-13 01:33

1 Attachment(s)
I noticed the following image comparison of the Large Magellanic Cloud in recent news reports. I leave it to interested readers to track down official accounts.

kriesel 2022-07-12 17:07

James Webb first images released [url][/url]

retina 2022-07-12 21:38

Why do the images have 8 spikes?

I can understand the 6 larger spikes. What are the other 2 smaller spikes caused by?

Uncwilly 2022-07-12 21:55

A good answer lies here: (

tServo 2022-07-15 13:09

hubble vs webb comparison pics
Neato !


kriesel 2022-07-15 15:29

[QUOTE=Uncwilly;609393]A good answer lies here: (

[QUOTE=tServo;609563]Neato !
[URL][/URL][/QUOTE]Ok, so since the geometries of the diffracting features are pretty well known, and there are generally bright near-point-source objects in the image for reference for confirmation/calibration, how about a third image, with the inverse fft of the JWST geometric diffraction applied? Granted, it is more complex than for consumer/pro cameras with approximately circular or symmetric polygonal apertures produced by multileaf irises, but diffraction correction is already being done for images from much lower budgets.

CaptureOne diffraction correction [URL][/URL]
Nikon & ViewNXi diffraction correction [URL][/URL]
PhotographyLife backgrounder on diffraction [URL][/URL]

retina 2022-07-15 16:04

[QUOTE=kriesel;609570]... diffraction correction is already being done for images from much lower budgets.[/QUOTE]You necessarily have to throw away information to "fix" the images.

If you only care about the images being used for artistic purposes then go ahead and mangle them to your hearts content. But if you care about the science then you won't retouch them just to make them pretty.

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