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JWST images

IB20

By IB20
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Gfamily

Gfamily

Posted
Posted
2 minutes ago, Ouroboros said:

Would I be right to assume that the narrow band filters select for emissions from particular elements? 

Hard to tell. 

If there's any real amount of red shifting in the target, it would be a lucky chance to get a spectral line matching the narrowband filter passband - so I would be sceptical that it would have any use for real far field targets. 

However, there may be some value for exoplanet atmospheric analysis, but I don't have any knowledge of what those spectra look like. 

[ A little knowledge is a dangerous thing, so anything I suggest could well come with a Hazmat warning]

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IB20
IB20

Well here’s an “OK” TEST image… If it doesn’t have spikes, it’s a galaxy 😃

CraigT82
CraigT82
ONIKKINEN
ONIKKINEN

Here is the full thing: Unbelievable!  

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Ouroboros

Ouroboros

Posted
Posted
Just now, Gfamily said:

Hard to tell. 

If there's any real amount of red shifting in the target, it would be a lucky chance to get a spectral line matching the narrowband filter passband - so I would be sceptical that it would have any use for real far field targets. 

However, there may be some value for exoplanet atmospheric analysis, but I don't have any knowledge of what those spectra look like. 

[ A little knowledge is a dangerous thing, so anything I suggest could well come with a Hazmat warning]

Yes, point taken  about red shifting. I hadn’t bought of that. 

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bomberbaz

bomberbaz

Posted
Posted
31 minutes ago, Richard_ said:

If you want to compare Hubble images with James Webb images, visit the below website. The two images are overlapped and you can move a slider to see Hubble or James Webb. Absolutely amazing! 

https://johnedchristensen.github.io/WebbCompare/

Screenshot_20220712-225616.thumb.png.c62ab5223f840210447e7f8119971c3f.png

they showed it at the reveal today, superb

 

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wimvb

wimvb

Posted
Posted (edited)

Fun facts

I just checked some technical data on the jwst.

fl 131.4 m

D 6.5 m

(F-ratio of 20! That’s one slow looking glass)

Mirrors coated with 0.1 um or a total of 48 grams of gold. That should be the cheapest part of the whole telescope.

Apparantly the various instruments  have a fov of about 1-2 arc minutes, the angular span of a ”grain of sand at arms length”. To me, that makes the deep field image even more impressive.

Edited by wimvb
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Padraic M

Padraic M

Posted
Posted
11 minutes ago, wimvb said:

Apparantly the various instruments  have a fov of about 1-2 arc minutes, the angular span of a ”grain of sand at arms length”. To me, that makes the deep field image even more impressive.

Someone on the NASA broadcast today said something like "we can't capture dark space" which I took to mean that wherever JWST was pointing, that 1-2 arcminutes (squared) is full of galaxies. That's a lot of galaxies.

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Gfamily

Gfamily

Posted
Posted
33 minutes ago, wimvb said:

Apparantly the various instruments  have a fov of about 1-2 arc minutes, the angular span of a ”grain of sand at arms length”. To me, that makes the deep field image even more impressive.

Imagine the SMACS 0723 image is up on someones iphone screen. 

Now imagine them standing on the goal line of a football pitch and you're on the other goal line.

That's the view. 

Hard to believe. 

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Sunshine

Sunshine

Posted
Posted (edited)

What boggles my mind about the deep field image is the galaxy count. Take for instance this run of the mill sample, are these galaxies even catalogued? how far away is/was this particular galaxy and does it still look like this? could it have collided with a neighbor and been ripped apart and we won’t see it for another how many billions of years? astounding image, I couldn’t be happier after closely following Webb progress for eight years now. It’s easy to forget that these disc shaped fuzzy patches are entire galaxies, GALAXIES!! each containing billions of stars which during their billions of year long evolutions could have been the birthplaces of who knows how many worlds and even forms of life on these worlds around their countless stars. How many civilizations could have come and gone within these galaxies in this one image? it would be incredibly naive to believe otherwise. When one looks at this image in high resolution and zooms in on these galaxies one by one, picking one out, it is impossible not to wonder what it’s stars have given birth to, if in doubt just think about what our star has managed.

AAA81290-169F-41E4-B2ED-59DB8E96BDE1.jpeg

C8C8CC72-E68B-400E-ABC1-199FE077A2C1.jpeg

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wimvb

wimvb

Posted
Posted
3 hours ago, Sunshine said:

are these galaxies even catalogued?

Most likely not. Catalogues are based on deep sky surveys, and these are done with much lower resolution, both from space telescopes and ground based telescopes. The fov of the jwst is much too small for use as a survey telescope. No doubt that the images that the jwst delivers will be used to catalogue the galaxies in them, but that will only cover "grains of sand" spread out over the celestial sphere. The "nearby" galaxies that act as gravitational lenses in the jwst deep field are at the edge of what amateur telescopes can image today. But at the fl that we use, these galaxies are only a few pixels across, and even these are not always identified in catalogues.

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Macavity

Macavity

Posted
Posted (edited)
55 minutes ago, Alien 13 said:

Nothing like a slice of Dr Becky to start the day, thanks.

Quite so! Gone are the days when scientific firsts were "ugly folks"
clustered round an oscilloscope at 2 a.m. waiting for some "blip"
on the two traces to coincide. (True story. lol) 🥳

🇬🇧 "Oh... There it is... That's jolly good... Fancy a PINT, Chaps"? 🍻

Edited by Macavity
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gorann

gorann

Posted
Posted (edited)

I have not followed all the entries on this thread, so maybe this has been discussed: JWST is an IR telescope and I got quirious. Has anyone here tried IR astrophotogtaphy? Googling it gives rather few entries, but this one got me interested:

https://www.cloudynights.com/topic/554666-nirha-preview-of-horsehead-project/

Edited by gorann
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