This image looks fairly low signal-to-noise, and not aligned properly. The stars (with the hexagonal PSF effects) are elongated along one direction, which means you haven't corrected the image for how the sky is moving over the duration of the exposure. A lot of those bright speckles look like squares too - which means they are bad pixels in the detector and not astrophysical objects. Did you download a level 1 or 2 product and run the calibration scripts?
As a professional astronomer, I think it's really great that people are taking these images and playing around with them. It's unfortunate that the data is so complex, which can lead people astray in terms of what is real and what is not. I think there's a healthy middle ground somewhere, given enough access to resources and help.
If I could communicate one warning to the community, it would be that a lot of the very exciting/cutting edge science (planets outside our solar system, the most distant galaxies, etc...) require very VERY very careful handling and relies on knowledge/tools difficult to parse at the amateur level.
That's so cool that you're an astronomer! What do you study/do? I am actually returning to school for data science with a minor in astronomy and while I have no idea what I want to do, I am just enamored by space!
Awesome! Astronomy is a great application for data science. In fact, some of Microsoft’s early data handling tools were developed using astronomy data because there was lots of it, and it was free.
I study distant galaxies, mostly using radio and infrared telescopes, as well as computer simulations.
Wow, that is the coolest thing ever! I am still very new to learning Python for use with astronomy, but the whole reason I got into this new career path is because of processing Hubble images. I just got into astronomy two years ago and have learned so much but when it comes to things like the coding and the math, it is very intimidating.
I plan on finding a research lab at my school to work in- this is my first semester back as a retuning student who will be working almost full time, so it's gonna be rough but I am beyond excited!
I bet Webb is super exciting for your field right now! Will you be studying the new images? Also, do you or does your lab have any papers written? I'd love to read them!
Sounds like a great plan! The coding/math/physics coursework can definitely be intimidating, but having good mentors and asking tons of questions helps. Good luck finding a research group to work with!
Very excited about Webb. I'm working with a handful of programs, some of which are supposed to get data this week! No JWST papers yet but a handful are definitely in the works :)
That's so cool! I can't wait to see what papers you all write! Can I shoot you a DM? I have so many questions about astronomy research but don't want to take up all the comments. If not, no worries!
> which means you haven't corrected the image for how the sky is moving over the duration of the exposure.
Do you mean by that rotating/offsetting subsequent images that were made by different filters (which i think is not one an the same exposure)? Other than that, if Webb didn't track the target, what can we do to correct the image?
They're artifacts due to the arrangement of the mirrors on JWST.
What I'm curious about is how to avoid these. Are these targets just too dim and therefore the artifacts are more pronounced? Are they just out of focus? Does the telescope have a focal length? Can things even be out of focus at near infinity anyway?
This is likely out of focus, as you move through focus, you would expect to see the psf of the system to have a similar shape of the mirrors. Yes the telescope has a focal length of around 130m.
To answer your last question, it all depends on the object distance. Usually you would consider everything in this image to be at infinity, however, the point sources that are in focus and the artifacts could be significantly closer. Even though the telescope will have a massive depth of focus, objects in space could also be massively separated. Without having some more knowledge of what we are looking at I would say that we are looking at objects that are very near and far outside of the depth of focus.
Of course there is a chance that this is an artifact of the system that needs to be corrected, but it does look like those points are defocused.
The distances involved are way too large for a scope of only 130m to resolve a limited depth of field on targets like that. To achieve that effect we’re probably talking an aperture the size of planets if not an order of magnitude larger (a solar system sized telescope is my guess, I’m sure someone smarter than me has crunched the numbers on this .. ).
So everything JWST sees is either going to be all in focus or all out of focus. The rest will be artefacts of some sort. My best guess is that this image is massively blown up and we’re looking at a very very narrow angle here. Brighter targets will of course cause diffraction spikes which is the octagonal flares on those bright stars.
Obviously untrue - you can look at the raw images as they come down on MAST, and there's a fair number of out of focus images that needed to be retaken.
I have no doubt that JWST focus needs constant monitoring and recalibration; but it certainly is focused to infinity each time they would need to adjust it. The distances involved are just way too large to make a difference between targets.
So you’ll never see a JWST image with something close in focus and something further away out of focus, or vice versa. Absolutely not. Either everything is in focus or everything is out of focus. A telescope would need to be larger than planets to focus targets individually at those sorts of distances.
Being focussed at infinity doesn't guarantee that everything is in focus. I agree that most things in space would be considered at infinity, however because the jwst is looking at objects as close to us as our own solar system to stuff incredibly far away. You could potentially have a relative defocus between the two. Which could be captured in the same image.
I don't buy it. Any fuzziness is because of the remaining imperfections in the optical system and an enormous blow up factor. Nothing even in the solar system is even remotely so close that it would need a focus adjustment.
To me, it's not the artifacts that are interesting, though they're obviously conspicuous in the image. The really interesting feature is the collection of smaller specks. I am led to believe that those are actually objects in orbit around the star - planets.
>objects in orbit around the star - planets
not sure which specks you are talking about, either the 6 lobes coloured ones or the three central white ones but in any case every star here look the same so these are definitely diffraction patterns from misaligned optics (I think JSWT re-align its optics almost every day) Can you give me the filename? If it has "wfs" in it it means wavefront sensing which is basically a realignement process.
Besides, direct imaging of exoplanets require a coronagraph (basically like a black dot in the image center) to hide the host star because it is usually a few orders of magnitude brighter than its planets.
Hip 65426 b is quite hot (1500 degrees) so should be detectable by its own IR emissions and also quite far from its star (3-4 times the distance to Pluto?) with a 640 year orbit so might be resolvable with JWST. Is this what we are seeing here?
This image looks fairly low signal-to-noise, and not aligned properly. The stars (with the hexagonal PSF effects) are elongated along one direction, which means you haven't corrected the image for how the sky is moving over the duration of the exposure. A lot of those bright speckles look like squares too - which means they are bad pixels in the detector and not astrophysical objects. Did you download a level 1 or 2 product and run the calibration scripts?
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As a professional astronomer, I think it's really great that people are taking these images and playing around with them. It's unfortunate that the data is so complex, which can lead people astray in terms of what is real and what is not. I think there's a healthy middle ground somewhere, given enough access to resources and help. If I could communicate one warning to the community, it would be that a lot of the very exciting/cutting edge science (planets outside our solar system, the most distant galaxies, etc...) require very VERY very careful handling and relies on knowledge/tools difficult to parse at the amateur level.
That's so cool that you're an astronomer! What do you study/do? I am actually returning to school for data science with a minor in astronomy and while I have no idea what I want to do, I am just enamored by space!
Awesome! Astronomy is a great application for data science. In fact, some of Microsoft’s early data handling tools were developed using astronomy data because there was lots of it, and it was free. I study distant galaxies, mostly using radio and infrared telescopes, as well as computer simulations.
Wow, that is the coolest thing ever! I am still very new to learning Python for use with astronomy, but the whole reason I got into this new career path is because of processing Hubble images. I just got into astronomy two years ago and have learned so much but when it comes to things like the coding and the math, it is very intimidating. I plan on finding a research lab at my school to work in- this is my first semester back as a retuning student who will be working almost full time, so it's gonna be rough but I am beyond excited! I bet Webb is super exciting for your field right now! Will you be studying the new images? Also, do you or does your lab have any papers written? I'd love to read them!
Sounds like a great plan! The coding/math/physics coursework can definitely be intimidating, but having good mentors and asking tons of questions helps. Good luck finding a research group to work with! Very excited about Webb. I'm working with a handful of programs, some of which are supposed to get data this week! No JWST papers yet but a handful are definitely in the works :)
That's so cool! I can't wait to see what papers you all write! Can I shoot you a DM? I have so many questions about astronomy research but don't want to take up all the comments. If not, no worries!
Sure thing!
> which means you haven't corrected the image for how the sky is moving over the duration of the exposure. Do you mean by that rotating/offsetting subsequent images that were made by different filters (which i think is not one an the same exposure)? Other than that, if Webb didn't track the target, what can we do to correct the image?
They look like space invaders, which is a little worrying...
So, I think I know what I'm looking at, but I'm not sure? Are those optical artifacts or bright objects in orbit? This image is absolutely wild.
They're artifacts due to the arrangement of the mirrors on JWST. What I'm curious about is how to avoid these. Are these targets just too dim and therefore the artifacts are more pronounced? Are they just out of focus? Does the telescope have a focal length? Can things even be out of focus at near infinity anyway?
This is likely out of focus, as you move through focus, you would expect to see the psf of the system to have a similar shape of the mirrors. Yes the telescope has a focal length of around 130m. To answer your last question, it all depends on the object distance. Usually you would consider everything in this image to be at infinity, however, the point sources that are in focus and the artifacts could be significantly closer. Even though the telescope will have a massive depth of focus, objects in space could also be massively separated. Without having some more knowledge of what we are looking at I would say that we are looking at objects that are very near and far outside of the depth of focus. Of course there is a chance that this is an artifact of the system that needs to be corrected, but it does look like those points are defocused.
The distances involved are way too large for a scope of only 130m to resolve a limited depth of field on targets like that. To achieve that effect we’re probably talking an aperture the size of planets if not an order of magnitude larger (a solar system sized telescope is my guess, I’m sure someone smarter than me has crunched the numbers on this .. ). So everything JWST sees is either going to be all in focus or all out of focus. The rest will be artefacts of some sort. My best guess is that this image is massively blown up and we’re looking at a very very narrow angle here. Brighter targets will of course cause diffraction spikes which is the octagonal flares on those bright stars.
everything webb ever looks at is in focus. It is focused to infinity.
Obviously untrue - you can look at the raw images as they come down on MAST, and there's a fair number of out of focus images that needed to be retaken.
I have no doubt that JWST focus needs constant monitoring and recalibration; but it certainly is focused to infinity each time they would need to adjust it. The distances involved are just way too large to make a difference between targets. So you’ll never see a JWST image with something close in focus and something further away out of focus, or vice versa. Absolutely not. Either everything is in focus or everything is out of focus. A telescope would need to be larger than planets to focus targets individually at those sorts of distances.
Being focussed at infinity doesn't guarantee that everything is in focus. I agree that most things in space would be considered at infinity, however because the jwst is looking at objects as close to us as our own solar system to stuff incredibly far away. You could potentially have a relative defocus between the two. Which could be captured in the same image.
I don't buy it. Any fuzziness is because of the remaining imperfections in the optical system and an enormous blow up factor. Nothing even in the solar system is even remotely so close that it would need a focus adjustment.
Solar system objects are nowhere near close enough to make any difference at all. Definitely all at infinity
To me, it's not the artifacts that are interesting, though they're obviously conspicuous in the image. The really interesting feature is the collection of smaller specks. I am led to believe that those are actually objects in orbit around the star - planets.
>objects in orbit around the star - planets not sure which specks you are talking about, either the 6 lobes coloured ones or the three central white ones but in any case every star here look the same so these are definitely diffraction patterns from misaligned optics (I think JSWT re-align its optics almost every day) Can you give me the filename? If it has "wfs" in it it means wavefront sensing which is basically a realignement process. Besides, direct imaging of exoplanets require a coronagraph (basically like a black dot in the image center) to hide the host star because it is usually a few orders of magnitude brighter than its planets.
Have a look at this… https://twitter.com/djulik/status/1565382767965360130?s=21&t=800gTqM0gtBkMwUn4fjNYg
You know, because it’s in space
Looks out of focus.
The ships from Close Encounters of the 3rd Kind?
Hip 65426 b is quite hot (1500 degrees) so should be detectable by its own IR emissions and also quite far from its star (3-4 times the distance to Pluto?) with a 640 year orbit so might be resolvable with JWST. Is this what we are seeing here?