Small clarification: At around 2:33, I said "each edge of Webb's mirror produces one diffraction spike in the image". It would have been clearer to say that each edge produce two spikes in the direction perpendicular to the edge - it's just like the struts we discuss later in the video. For example, one edge would contribute to spikes 2 and 5 (as they are labelled at 2:11), and the edge opposite contributes to the same spikes and makes them brighter. Hope this clears that up!

@kiyonmcdowell5379

2 жыл бұрын

But would the spikes obscure the images of the planets circling the star

@Bless-the-Name

2 жыл бұрын

Should have installed spinning struts.

@sandeepnath9504

2 жыл бұрын

I am God himself and I say you are right about the edges of the mirror and also you won't find life on Alpha centuri You will find it in one of its next planets satelites. Also an humble request to all of you space explorars please stop looking inside my underwear with infrared telescopes ask me things directly next time till then peace...!!!!😇😂

@789563able

2 жыл бұрын

Damn straight. I’m getting so paranoid about them looking in my undies that I had to stop wearing them. But summer is coming so I should be OK.

@somedumbozzie1539

2 жыл бұрын

Even after Hubble was repaired it tool them some time to dial it in and when they did it was breath taking. They are easy to process out with out losing to much resolution is just a question run time. Its the planets around the stars that matter I would not be surprise to hear the news that a planet with artificial light coming from has been discovered.

Thanks so much for answering the question that's popping into my head everytime they show an updated image. The diffraction is so distracting I was thinking it was a flaw in the telescope. You're video is the first I've come across to address this question. I'm an instant fan. Thanks again!

@ChrisPattisonCosmo

2 жыл бұрын

Thanks so much, and I'm glad it helped :)

@instamdgram

2 жыл бұрын

Your*

@EverythingYouKnowIsWrong

2 жыл бұрын

@@instamdgram Your right. Thanks four policing my typos.

@mr.boomguy

2 жыл бұрын

@@EverythingYouKnowIsWrong lol, was that "four" intentional after that 😆?

The reason for several slightly disaligned spikes are that these are position dependent over the CCD. As you may notice, this image is not a single frame, but a coadd of several individual exposures with different pointings. As you put the star across the CCD the spikes are slightly different, creating this effect in this coadd image

What I'm really astonished by is how, in spite of being zoomed in on that one single star, you can very clearly distinguish infrared light sources from MANY, MANY, stars in the background that aren't in focus but still have very vivid clarity

Exactly the video I was looking for after the recent image release. Thanks!

Every object in that image has the same set of diffraction spikes present. The reason you notice it for the target star is because it's extremely overexposed relative to the rest of the field. If you adjusted the exposure to make the target star appear normal, you wouldn't see most of the other details. If you want to see faint spikes around some of the other stars, look up the original image on the NASA site.

@ChrisPattisonCosmo

2 жыл бұрын

Exactly! The spikes represent some small percentage of the light of the object, and since this one is so bright to Webb the spikes look huge, for the fainter objects in the background the spikes are much smaller.

@winklethrall2636

2 жыл бұрын

@Amilton Sánchez The link I posted got blocked or deleted, but you can find it if you google the terms "nasa telescope alignment evaluation image".

@AudreysKitchen

2 жыл бұрын

@@ChrisPattisonCosmo that’s really reassuring actually 😅

@lubricustheslippery5028

2 жыл бұрын

It still would be better if it was one big homogeneous mirror and no struts to minimize diffraction. That would be impossible to do i don't ask for the impossible.

@AFRoSHEENT3ARCMICHAEL69

Жыл бұрын

Go watch the stage lights of Michael Jackson live in Bucharest. Notice how they specifically only make hexagrams and only at random moments. But they are perfect looking hexagrams. These patterns correspond to the star of David or star of life or flower of life patterns. Cameras are based off the eyes. The first camera was the camera obscura.

thanks for this amazing quality videos! my fav channel about JWST related stuff for sure!

@ChrisPattisonCosmo

2 жыл бұрын

Thanks for much!

I've definitely been wondering what causes those spikes. Thanks for making such a clear video about it :)

Ver good clear description with no padding - very refreshing !

@ChrisPattisonCosmo

2 жыл бұрын

Thanks very much!

Beautifully explained- thanks! 👍

@ChrisPattisonCosmo

2 жыл бұрын

Thanks a lot!

Wonderfully explained, thank you so much! :) After the release of the 5 images by Webb, I must say the diffraction spikes are something so pretty that I don't mind them at all ;) They add this 'starry' effect ;) I like them! :)

Well done great vid👍

@ChrisPattisonCosmo

2 жыл бұрын

Thanks a lot :)

So excited for these Images this summer :)

@ChrisPattisonCosmo

2 жыл бұрын

Me too!!

100k views? Damn dude this video blew up. I'll check out the rest of your channel this was a good video

@ChrisPattisonCosmo

2 жыл бұрын

Haha, thanks a lot! :)

Really enjoyed this video.. im just amazed that everything has gone to plan .

@ChrisPattisonCosmo

2 жыл бұрын

Thanks! I agree it's incredible (almost unbelieveable) that nothing has gone wrong (yet!)

Thanks! I was wondering about that.

Cool. Very clear and easily understandable explanation. Love it.

@ChrisPattisonCosmo

2 жыл бұрын

Thanks very much! :)

Good video! I was wondering about this topic. First time view here too if I remember right.

@ChrisPattisonCosmo

2 жыл бұрын

Thanks, and welcome!

Great youtuber starting spoted!!!

@ChrisPattisonCosmo

2 жыл бұрын

Thanks! :)

Nice job, you spiked my interest for sure 😄😂

@ChrisPattisonCosmo

2 жыл бұрын

Ha, thanks!

Great video!

@ChrisPattisonCosmo

2 жыл бұрын

Thanks a lot! :)

Congrats on getting so many views!

@ChrisPattisonCosmo

2 жыл бұрын

Thanks, it completely surprised me! :)

Excellent and great information. Thanks

Great video, super informative. Thank you.

@ChrisPattisonCosmo

2 жыл бұрын

Glad you enjoyed, thanks for the comment :)

Can't wait for more images to come out to see how they turn out. Thanks for the very insightful explanation.

@ChrisPattisonCosmo

2 жыл бұрын

I can't wait either!!

@Hamsters831

2 жыл бұрын

@@ChrisPattisonCosmo haha. Ya. Come to think of it. Actually is it possible those 3 or 6 lines however u look at it are caused by the edges between the mirror panels since there are so many and will each create their own defraction which overlapped into this effect. Those tiny lines u pointed out.

The image around 5:35 answers my curiosity with this subject and until I found your video I hadn't even remotely come close to finding that article. Thanks for the great explanation!

@ChrisPattisonCosmo

2 жыл бұрын

Thanks! I'm glad it helped!

Excellent clear explanation. Nicely done.

@ChrisPattisonCosmo

2 жыл бұрын

Thanks very much!

Excellent detailed presentation. But some of the smaller stars have diffraction spikes that are in directions 30 degrees away from those of the main central star. I notice that the overall shape of the complete main mirror is hexagonal but rotated 30 degrees from the individual hexagonal elements. Is this connected to the above effect? Confusing!

Great explanation, thank you

@ChrisPattisonCosmo

2 жыл бұрын

Thanks! :)

Fantastic explanation and video!

@ChrisPattisonCosmo

2 жыл бұрын

Thanks so much!

interesting info, cool!

This was my question. I was supposed to ask my professor regarding this.Thanks for your answer

Excellent explanation. So I wasn't the only person concerned with the spikes.

@ChrisPattisonCosmo

2 жыл бұрын

Thanks! Rest assured the spikes won't be so bad when Webb looks at most of its (much fainter) targets :)

Thanks so much from a new subscriber. Those spikes annoyed me, but now I know why they appear, I'm comfortable with them.

@ChrisPattisonCosmo

2 жыл бұрын

Thanks! At least it's always going to be easy to know if a picture came from Webb because they will all have the 6 spikes!

From the previous alignment images, I get the impression the JWST team was using the shape of the diffraction spikes as an indication of how good the alignment is. Is that correct?

@ChrisPattisonCosmo

2 жыл бұрын

I believe so!

@kathrynck

2 жыл бұрын

I "think" that they were using the diffraction spikes specifically to align the mirrors together. Basically move one mirror at a time, until all the compound images of the star are on top of each other, and then use the diffraction spikes to further tweak, keep tweaking them one by one until all the spikes are overlaid on each other. I suspect that the multi-line effect in the diffraction spikes, means there's still room to further tweak the alignment (it may be at it's aligning limit though, I dunno). The fact that there are previously never seen galaxies in the background is a sign that it's going to add a lot to our telescope capabilities. I mean some of those, you can clearly see the shape of the galaxies, and those weren't even a blob or a spec in hubble's eye. The spikes can be minimized by exotic software in post processing, but a lot of types of research won't need this extra step. I've done some noise-minimizing in regular low light/high ISO photography, by having a camera take 2 images in rapid succession, one with a closed aperture, and using the black image as a "noise map", to help identify & remove noise from the open aperture image. But that doesn't remove spikes. NASA has much more fancy software solutions than this though ;)

Some amateur telescopes use curved secondary vanes. This does not eliminate the spikes; it just smears them out. There are obstruction free reflector designs like the Chiefspiegler, but these are rare and are made in longer f ratios.

@ChrisPattisonCosmo

2 жыл бұрын

The curves vein ones are pretty cool! A refractor telescope doesn't have diffraction spikes from struts (because they have no struts), but they're too heavy to get into space at present

Great explanation.

@ChrisPattisonCosmo

2 жыл бұрын

Thanks! :)

Having had an interest in astronomy for the past 54 years, I already knew this, but kept pondering what confusion the pic would cause for many. Subscribed.

@ChrisPattisonCosmo

2 жыл бұрын

Thanks very much

Thank you for this. I learned something today and it's only 9:22 am! :)

@ChrisPattisonCosmo

2 жыл бұрын

Glad you liked it! :)

Great video

@ChrisPattisonCosmo

Жыл бұрын

Thank you! :)

I very much appreciate the straightforward explanation. Those spiky rays did bother me a bit.

Just found your channel. I like the way you present your content. I subscribed and look forward to your future videos. It is an exciting time to be a human 🚀

@ChrisPattisonCosmo

2 жыл бұрын

Thanks so much! The next few years will be very exciting for astronomy - a lot of amazing telescopes are coming online soon!🤩

Thanks Chris

By turning the telescope and taking another picture, you can retrieve that information and overlay it on the original picture, to get the whole image without the spikes. You erase the spikes on each photo or many photos. Using a different picture to replace the parts you erased. But it is easy to just turn the telescope to a point where the spikes don't interfere with what you want to study. So no problem.

@_.Madness._

2 жыл бұрын

You are a genius.

@vencdee

2 жыл бұрын

But it's more complicated than just removing it by sophisticated postprocessing. I think that it would be relatively easy, because the spikes are just function of size and brightness and exposition. Anyway, for some specific targets with details around the stars (nebulas or even planets) it might be better solution to rotate the telescope by e.g. 15 degrees just by using gyros.

@unitrader403

2 жыл бұрын

im pretty sure rolling the JWST to get two photos where the spikes dont overlap is impossible for most targets, since one side must always face the sun, and the Mirror is fixed in place. So the only way to get images where the spikes dont overlap is to take shots about a month apart, and in roughly polar direction. For stuff in equatorial direction the spikes will pretty much always overlap, unlesss you rotate the telescope in such a way that the mirror gets exposed to sunlight...

All that information is one test image. The potential of this marvel is mind blowing! Thank you for the video. I had always wondered what those spikes were!

@ChrisPattisonCosmo

2 жыл бұрын

I agree it's an incredible image!

Congratulations for 559 subs

@ChrisPattisonCosmo

2 жыл бұрын

Thank you so much 😀

@joy_6.9

2 жыл бұрын

@@ChrisPattisonCosmo most welcome ☺️

This is also similar to the concept wherein “bokeh” in a photo are tiny representations of the shape of the cameras aperture. This is basically a bokeh shape with diffraction patterns overlaid.

Cool story bro 😎

Another awesome video! 🌟

@ChrisPattisonCosmo

2 жыл бұрын

Thank you my dude!

Personally I love diffraction spikes. Especially when they're split spectrum and accompanied with some awesome music.

I'd like to know more about the salt based lenses that are used on the telescope

Great show! Optic technology should correct. Why are some spikes much longer, thicker etc, and variate day to day?

The lines you mention at 5:40 may be due to phase shifts between the light bouncing from different mirrors at not equal depths (maybe small as a wavelength fraction) and so producing phase addition and substraction (cancellation). I guess. This procedure of mirror phase alignment, I heard that the telescope can perform due to the mirrors actuators, but at the time that this photograph was taken, the mirrors I believe were not yet adjusted phase-wise.

@ChrisPattisonCosmo

2 жыл бұрын

Oh that's interesting, thanks!

Perfect explanation. I suppose that the special software will be used later to remove the spikes without loosing nearly any details. Because for every bright object they are aligned in same directions and are proportional to the size/brightness of object, it should be relatively easy set of algorithms...

@h.dejong2531

2 жыл бұрын

The spikes can be removed, but you'll lose some of the detail in the image.

Was wondering with the analogy of using slit to explain mirror diffraction, the slit experiment usually uses very small slit (on the order of the wavelength), but mirrors are very large. Will they have the same diffraction pattern?

Isnt there a way to collapse lights wave function and get rid of the pattern.

Top!

Great video! One suggestion... a better teleprompter.

@ChrisPattisonCosmo

2 жыл бұрын

Ha, you're not wrong, I could have set it up better!

Thanks for your explanation. I appreciate it very much!

I think that star should be awarded a name for having been so integral in this project.

@ChrisPattisonCosmo

2 жыл бұрын

I completely agree! Any name suggestions?

La longitud de onda es tan pequeña que haría falta una lente mucho mayor para que no se produjera la difracción de la onda.

Thanks! It however raises another question. Why is the sensor supported by a tripod? I understand the structure stability the shape provides but in the absence of any loads upon it in the vacuum of space suggests one arm might have been enough. Are three used primarily to allow the sensor location to be aligned more accurately?

@EmersonSecondary

2 жыл бұрын

The loads from liftoff, and the precision movements required to focus the lens mandated a stronger arm then a single one.

@Bendigo1

2 жыл бұрын

Each of the arms can move independently so they can fine tune the focus. The tripod also provides stability. with exposure times as long as they use, every bis of stability counts.

@HotelPapa100

2 жыл бұрын

There's also the issue of vibrations. Having the secondary mirror as an oscillator at the end of a cantilever strut, while having an oscillating mass in the form of the cryocooler piston on the craft... not good.

@dovos8572

2 жыл бұрын

@@HotelPapa100 vibrations are so bad that they are close to 0 K on the mirror side of the telescope. and they need it because of the faint rays they want to capture. they are so faint that the heat of the telescope itself would overexpose the image everytime.

@minimovzEt

2 жыл бұрын

There's a bunch of reasons, for example, when the sensors are getting deployed, there's the inertia from the weight of the sensor, which is heavy, having for example just one arm to put that in the correct position would cause flexing in the arms and it wouldn't be positioned exactly where they would've wanted, any orbit maneuver that would be needed would also create vibrations and change the position of the sensors, the design basically needs to be the exact opposite of what mechanical engineers design here on earth, it needs to be very very hard because they need the precision.

Is this holes in red background 1:07 ghosting effect?

When can we expect images? I know you said summer 22. But any update ?

@ChrisPattisonCosmo

2 жыл бұрын

I'm afraid I haven't heard any updates. Everything is going well so far, the coldest instrument on JWST (MIRI) has just reached the target operating temperature of "below 7 kelvin". Some calibration of that instrument will happen next, followed by commisioning of everything, and then science can start. I am expecting/hoping the first science images to be released in June or July this year!

Man i thought the JWST pictures were already TOP NOTCH qualitym, the best possible, but there is still a lot of room for improvement i didnt actually think that wow!

Thank you so much, Chris! One question still lingers in my mind: why exactly is the number of spikes twice the number of sides of the aperture when odd and equal to it when even? I don't quite understand.

@ChrisPattisonCosmo

2 жыл бұрын

Thanks for the great question! It's because each edge produces two spikes, perpendicular to the edge. For even sided apertures, opposite edges both produce spikes, but they overlap, so the two edges combine to only give two visible spikes. For odd sided shapes, there aren't any opposite sides, so no combining and each edge gives two spikes. Does that make sense?

@ambicagovind6986

Жыл бұрын

@@ChrisPattisonCosmo Oh yes, thanks very much!

The foreground while magnitudes dimmer had no issues. Sure the focal process some type of filtering is not being used for citing it in.

In addition to the 8 large spikes there are many tiny spikes. Do we know what causes those? If they were all digitally (or theoretically) removed would we have a circular image corresponding to the size of the star?

@h.dejong2531

2 жыл бұрын

The star is smaller than a single pixel. You get some leakage into adjacent pixels.

3:12

The image is akin to one of those old TV sign-off test patterns, except this is way cooler.

i cant wait for an updated andromeda image with webb's quality

@ChrisPattisonCosmo

2 жыл бұрын

Me too, it will be amazing to see through the dust of andromeda in the detail that Webb will give!🤩

Cool. Thanx for the explanation, which in my (computer technology instructor) opinion **always** counts the graphics as an inseparable, integral part of the explanation. These graphics were very good for [my] understanding the talk. I always thought the struts were the cause of the patterns, not both struts and mirror design/construction. Anyhoo, does it degrade the total quality of data, for whatever analysis you're interested in, if the diffraction pattern is digitally removed before further data analysis is done? Although in Hubble photos the star patterns add a certain flair to the image printed in the magazine, or shown on the web, I personally wouldn't miss them if they were digitally removed first.

@ChrisPattisonCosmo

2 жыл бұрын

Thanks very much! It does degrade the image a little to remove the spikes. A bit of contrast and resolution is lost, especially in the centre of the image. This is why they are usually only removed if researchers really want to study the a star itself or the immediate space around it. Most of the time the spikes will just be in foreground stars when Webb looks at most distant (and faint) objects, so they shouldn't be a problem most of the time.

@abcde_fz

2 жыл бұрын

@@ChrisPattisonCosmo Cool deal. Thanx! I guess I sort of knew why they never 'filter' out the effect, but it's better to know for sure! :-)

It's spike level is over 9000!!!!

I was puzzled by these as well. I thought these spikes only appear on terrestrial telescopes' images due to the earth atmosphere and that was one of the main reasons we send telescopes in space. Now we have a new story.

@annoloki

2 жыл бұрын

The atmosphere causes more of a haze, although this is now quite correctable by using dynamic mirrors that change shape to counteract the distortion in the wavefront of the light. The bigger problem is that the atmosphere simply blocks much of the spectrum, so you need to be outside of the atmosphere to see those frequencies. These are more akin to lens flare you get from normal cameras.

The only thing is the two bottom struts are not as wide as the starlight suggests. If you notice they're both near the center, bottom. They're each one hexagon away from the center. The starlight suggests they're much wider spaced at the 4 o'clock position rather than 5 o' clock. Chris Pattison, can you explain this? Thank you

@ChrisPattisonCosmo

2 жыл бұрын

Greeat spot, I should have commented on this in the video. I don't know for certain why this is, but it could be to make sure the diffraction spikes from those stuts overlap exactly with the ones already produced by the mirror shape.

Just a slight point: the struts on Webb are not at 120 degree hence their diffraction pattern wouldn't be as you show at 5:18 ie 6 equally spaced spikes. If they were then they would not line up with the 6 spikes produced by the mirror edges. The two sets of spikes would be offset by 30 degrees. However, I notice from the final image at 5:36 that the spike pattern is exactly that which is seen in the actually photo. I guess this unequal spacing cause both sets of strut patterns to line up - apart from the horizontal pair? (Like your video - thought it was clear and informative.)

@ChrisPattisonCosmo

2 жыл бұрын

This is a really interesting point that I should have mentioned, thanks for pointing it out! I honestly don't know for sure why the struts are like that, but I would guess that you are correct, to overlap some of the spikes and minimise the effect of them. Either that or it could be something to do with the unfolding process or precsion of the mirror, I will try to find out!

@neil6477

2 жыл бұрын

@@ChrisPattisonCosmo Thanks for replying Chris. One other thing which makes this issue more complicated than normal is that the exact diffraction pattern produced by the struts is also dependant on where the struts are with relationship to the focal plane of the instrument. All the analysis that I have ever come across assumes that the 'spider' lies in the same plane as the secondary mirror. On the JWST however they are angled from the reflecting mirror plane down towards a plane close to the main mirror. I am unsure how this affects the diffraction pattern (actually that's a lie - I am not unsure - I've no idea) but I am certain it would complicate the issue.

@cstockman3461

2 жыл бұрын

Yep, the struts on Webb were designed to create that line up and fewer diffraction spikes

@neil6477

2 жыл бұрын

@@cstockman3461 Thanks.

I see diffraction spikes when looking at lights. They go away somewhat when I squint. It makes driving at night difficult, and looking at certain signs and light signals an unreadable mess. Think of the big orange ones with lights that scroll, or restaurant signs. Just blurs. Everything else is crispy clear.

@jamespong6588

Жыл бұрын

It's because you have astigmatism, you need prescription glasses when you drive at night

Are thorn's and spear's and gunshell's a problem?

As an amateur astronomer, I've never been too upset by diffraction spikes...in fact they sometimes add to the enjoyment when viewing visually. (The Pleiades look awesome with diffraction spikes as does Sirius). The one thought that comes to mind...do the diffraction spikes contain information about the subject star? Obviously there will be chromatic and spectrographic information, but I wonder if the presence of protoplanetary discs or even planets could be extrapolated from the spikes. Sounds like a good subject for a thesis if there's any astronomy students looking for a doctorate!🤔

@ChrisPattisonCosmo

2 жыл бұрын

That's a super interesting question! I agree the spikes make it look great, I wouldn't want them removed from most photos! I suspect the spikes just wash out information, but maybe someone who knows more than me would be able to retrieve some information from them.

@sharkking9679

2 жыл бұрын

afaik - In the Visible Spectrum you can analyze the Spikes. They have different colors and therefore can tell roughly about the composition of the star.

Where can I get info on black body radiation spectrum for matter and plasmas

@ChrisPattisonCosmo

2 жыл бұрын

Wikipedia is always a good starting point!

Couldn't those thin lines within the spikes be produced by the different distances/angles of the mirrors to the sensor? Those would be interference patterns.

I learnt diffraction only occurs when the obstacle size is smaller than the lenghtwave. Altho here it seems its not the case? Why does it happen then?

in 70s space movies spiky stars were exactly what we saw. finally the future is here!

NASA said they used Fourier Series to align the edges of hexagonal mirrors. Can you explain that?

@ahriman935

2 жыл бұрын

Every mirror (or rather: every edge) creates some diffraction signal that is visible in the picture. Now, there are several mirrors and even more edges in the entire JWST's optical system and when all those combine, in the picture you will see a SUM of all those diffraction patterns. You won't be able to easily discern which individual diffraction signal is where, and which element of optical system created it, simply because they're all mashed together in some way. That's where Fourier transformation comes into picture (pun entirely intended). Basically, if you know that a given output signal is in fact a sum of various different periodic signal (think waves of different amplitudes and frequencies combining into a single, large wave) you can very neatly decompose that signal into those EXACT component waves. You can find plenty of pictures that illustrate how it works in the internet. In this case, you take light visible in the picture (signal), you run it through Fourier transformation and you WILL get all the underlying individual signals (diffraction spikes from every individual element in the optical system). Which obviously helped NASA calibrate the telescope much faster than if they just did trial and error. How does it work on mathematical level? Magic. No, seriously, it just works. But it involves calculus and literal imaginary numbers, so don't delve too deep into it, that way lies madness.

Just a silly question: knowing the origin of those spikes, why cant we compute back the (spike) photons to their "real" location and thus get an undisturbed image?

@A_piece_of_broccoli

2 жыл бұрын

they can, but as he said in the end of the vid this picture was just for engineering purposes only. one of those purposes is testing their abilities to do exactly what you suggested.

@Telephonebill51

Жыл бұрын

Of COURSE they can! It's a totally digital image; NOTHING is in there that they don't WANT to be in there. If you'll notice, not ALL stars have it, so it's NOT caused by anything they can't fix. The popular "Cross Star" filters for film cameras led to the idea, I'm sure. Yeah, they could clean them up, and likely will at some point and claim a success over the 'problem' they finally fixed.

The time has come

Great stuff man was hoping u might address the black dots in some of the galaxies behind the star are those planets I'm very interested in what that might be maybe somebody can help

@Angel-kf4sg

2 жыл бұрын

I wondered what that was too….does anyone know what the black dots were?

@ChrisPattisonCosmo

2 жыл бұрын

This is a great question that I don't know the answer to! They won't be planets as they would be too small and faint to see like that. I would guess they are artefacts due to the telescope, but I will ask around and leave another comment if I can find out!

@supersonic3675

2 жыл бұрын

@@ChrisPattisonCosmo maybe a civilization type 3 that dun build something around a star to harvest its energie 🤷‍♂️ but yea if you find something out plz let us know thank you

@RockStump

2 жыл бұрын

I would guess those are areas that were specifically blocked out because they were close to the brightness (or brighter) of the star that they were trying to image.

Thank you Chris for explaining the source of those spikes, to be honest when I first saw that image I was not at all impressed as I was expecting a clear image of a spherical star, not a spikey star. I wonder why they can't produce clear images without those spikes, I know they'll just say it's the laws of physics/diffraction etc etc but we have supercomputers now which should be able to remove those artefacts surely? If we know what causes them we should be able to remove them?

@ChrisPattisonCosmo

2 жыл бұрын

I think diffraction will always happen for a reflection telescope like Webb. Refraction telescope don't have the same problem, but are WAY heavier and so putting one in space just isn't feasible yet. They can remove the spikes after the images are taken, but that process also loses some contrast in the rest of the image. For fainter objects (this star is deliberately way too bright here), the diffraction is a much smaller issue and it won't affect the science being done!

@nearearthobjects3089

2 жыл бұрын

@@ChrisPattisonCosmo I miss a viewer like you . I had not even one clever comment in 2 months .

@nekogod

2 жыл бұрын

There are certainly scenarios where you would want to remove them, but the process can introduce noise and cause other details to be lost, so depending on the application and the science being done they are not always removed even though we have the capability. Dr. Becky has a good video explaining this.

Its incredible how much details must be considered by the engineers in the first place. And its also stunning that they did.

I'm just wondering What would happen if we used telescopes with magnets to gold the mirror in place? Would it remove the strut problem, and get a somewhat better image, still with with the lines from the mirror shape

@ChrisPattisonCosmo

2 жыл бұрын

I think at the moment they can't get the precision needed for calibration if they used magnets, so they have to use struts for now. Also, in the launch, I think the struts also keep things from vibrating and rattling too much. In the future though when tech is even better, I think this will be a great solution!

@mr.boomguy

2 жыл бұрын

@@ChrisPattisonCosmo Thank you for the answer. Btw. Speaking of telescopes, and call me crazy, but do you think a, what I call a, "Light minute Telescope" is possible. We have telescopes all over the earth, so having a area of 17 987 547.5 km radius full of thousands of Hubble sized telescopes where the JWST is at. What's the limit for telescopes?

I see them spikes two house down the block. Lol it reminds me of that everytime I watch videos on jwst.

I can see those when my eyes are tired and I look at a street light or something

My vision is not the greatest and I have always wondered what those two, vertical spikes were caused by when I look at lights. I assume it is my eyelids doing this when I squint. Christmas lights do this when I'm not squinting though so I'm not sure.

I'm a retired professional photographer. No matter how much you try to technically explain the "star burst" effect, it's an expensive optical distortion. I'm sure it will be corrected soon via computer jiggery pokery, though I was expecting the JW telescope to do this internally considering its advanced onboard computers.

@h.dejong2531

2 жыл бұрын

In this particular image, the star was overexposed, and the light curve is logarithmic, to make the spikes as bright as possible, because there's information on how good the mirror alignment is in those spikes. Science images won't be overexposed or use this light curve.

Webb's my boy!

What about the sepia color? Will that be a permanent fixture of future photo's? I hope not.

@ChrisPattisonCosmo

2 жыл бұрын

Nope, that was just for calibration images, these new ones will be full colour! :)

Just realized that 2 of the struts are closer to each other exactly because diffraction pattern will be overlaid by the pattern from mirror.

Can these be removed? Re by computer calculations?

@ChrisPattisonCosmo

2 жыл бұрын

They could be, yes, but at the cost of a little sharpness in the remaining image. The spikes are so bad here because the star is WAY brighter than anything Webb will normally look at. For fainter objects, they aren't a problem and the science done won't be affected :)

What about the smaller versions of the spiky star that show up in the image? There are about 15, of different sizes, some of them with black spots. I'm assuming that they are some other optical artifact, but haven't seen it discussed anywhere. I am also assuming that they won't be a problem for scientific observations, because they only happen because this star was so bright, so saturated. But that's a lot of assumptions.

@ChrisPattisonCosmo

2 жыл бұрын

The smaller objects with spikes are background galaxies that are still bright enough to cause visible diffraction spikes, through exactly the same processes! The black spots are also some optical artifact or compression issue as you say, they are real objects!

Since the image has a systematic distortion, is there going to be a systematic correction to fix the image? And for the parts of the image where the "spikes" cover important astronomical information, how will scientists recover that information?

@Sarconthewolf

2 жыл бұрын

By turning the telescope and taking another picture, you can retrieve that information and overlay it on the original picture, to get the whole image without the spikes.

@ChrisPattisonCosmo

2 жыл бұрын

The spikes could be removed, but you lose a bit of detail and contrast in the remaining image if it's done, so most of the time they are left in.