Did you see the news that all of the instruments are aligned now?

Check out this comparison of one of the newly released calibration images from the MIRI instrument compared to images taken of the same region of space by the WISE and Spitzer space telescopes! Look at that resolution! So many newly resolved stars and structures! 🤩

I can't wait for all the new discoveries we'll make with JWST! data starts in only a couple months!

(Image from @/AndrasGasper on birdapp)

@_astronoMay wow. We’ve been waiting for this kind of comparison so long. Thanks for sharing.

@_astronoMay oh she’s gonna give us so much! Worth every penny.

@_astronoMay Dayum!

In all seriousness, using backcasting / retrospective analysis, what have been the most consequenctial results of improved astronomical observation in the past? How does this illuminate (so to speak) what we might gain here?

Thoughts that occur to me:

Kepler's precise measurement of orbital movements -> orbital mechanis.
Gallileo w/ astronomical observations -> recognition of solar system bodies as nonperfect (spots on Sun, craters on Moon), and systems-within-systems (moons of Jupiter).
Early estimates of speed of light (changing times of transits of Jovian moons resulting from varying Earth-Jupiter distances).
Validation of special relativity through observations of solar eclipse.
Solar spectra, determination of composition of Sun, discovery of Helium, origins of stellar chemistry.
Redshift measurements, Hubbert's Constant.
Cosmic Background Radiation -> Big Bang.
Cephid Pulsars.
"LGM" rapid pulsars -> neutron stars.
Radar determination of Venus's rotation.
Infrared sensing and determination of surface temps --- planets, stars, etc.
Exoplanet detection
NEA detection & warning.
Neutrino detectors.

(Very partial list.)

Is there some sort of official Astronomical Compendium of Major Discoveries out there?

Major findings, of, say, WISE, Spitzer, Chandra, Hubble (scope), etc.?

@dredmorbius I'm not sure if there is a compilation of all the major discoveries of each observatory! My favorite would probably be the Hubble Deep Field though!

@_astronoMay On HDF: what's the scientific content of that image?

I mean "it's full of starsWgalaxies" is interesting from a visual / aesthetic basis, but scientifically what does it show?


Well, it shows that galaxies formed quite early in the universe and that there are a hell of a lot of them.


@_astronoMay Does the fact that JWST is an infrared telescope mean that images will be essentially "monochromatic" like the ones in your tweet, or will they be digitally artificially colored to depict different frequencies within the infrared mapped to visible colors?

@futureisfoss @WestCoastBirder nearly all telescope images are by default monochromatic! The only way we can get color is by using filters and then combining them on a computer later.

There are some telescopes that also record the "color" of the light too in the form of the energy of each photon, but these are x-ray telescopes.

For JWST we have quite a few filter options on the different instruments to take pictures with, but they can also be combined with data from other telescopes too!

@_astronoMay so freaking cool I can't wait to see what we see! 🎇 🌠 🌟

@_astronoMay I think WISE was before Spitzer but WISE was a small explorer and for doing an all sky survey rather than spot imaging. Still it is a very impressive improvement.

@hankg WISE was actually launched after Spitzer! In fact by the time WISE launched, Spitzer had ran out of coolant and couldn't look at as long of wavelengths anymore because its own heat got in the way.

But you're right, WISE wasn't designed for high resolution imaging, but still an amazing comparison because we've never seen this region of space like this!

@_astronoMay Yeah that's what I meant. I"m not sure how I flipped that lol. JWST is going to be an amazing telescope indeed!

@_astronoMay Spectacular! Thanks for sharing. I must say, I’m loving what I find on Mastodon (and the replies, too!). I don’t think this type of post is as visible on … ahem … other social media sites. 😉

@_astronoMay That's incredible! I can't wait for the discoveries and theoretical breakthroughs that I can pretend to understand while I read cool articles in years to come.

@_astronoMay hnnng, I've been waiting for a JWST comparison pic

@_astronoMay can you explain the numbers at the bottom? The resolution gets higher and higher as we move left to right but these numbers go up and down which is confusing.

@Natris1979 @_astronoMay wild guessing because I hope to be corrected: the wavelength of light each telescope detected.

@IslandUsurper @Natris1979

Correct! That's the wavelength of light in each image.

We typically use filters to only collect very certain colors of light at a time so that we can later see how objects in space change when observed in these different colors. This helps show us, among other stuff, what the objects are made of

These are all infrared wavelengths, which is a type of heat.

Very good image detail.
Some stars are now displayed as eight rays :)

@Lafiel yeah, doesn't that look cool! This has to do with the shape of JWST's mirrors! Because they're not a circle, when we look at a point source like a star it doesn't show up like a circle on the detectors. There's a bunch of fancy physics that goes into this, but this image is an example of what shapes different mirrors turn point sources like a star into

@_astronoMay @Lafiel I was going to comment on how beautifully JWST’s structure is mirrored in the stars’ patterns. Great comparison in those pictures!

@_astronoMay have to wait till summer =( I feel antsy myself!

@_astronoMay Amazing evolution, thank you for sharing! What region of space are we looking at?


this is part of the Large Magellanic Cloud, a dwarf galaxy that orbits our Milky Way!

@_astronoMay Wait, this is another 𝒈𝒂𝒍𝒂𝒙𝒚 😮 🤯!? That's amazing - I'm clearly not up to date re: stellar photography, did not know photos of objects as distant as this were even possible. Super impressive, thank you so much for elaborating.

@_astronoMay I can't figure out whether mirrors alignement operations are completed or other related work is presently underway. Any updating ? Thanks.

@_astronoMay #JWST Yes, got it in the NASA web site. Various instrument commissioning ongoing. It looks like it will take a couple of months ti complete. Findings on this calibration process may not be of great interesse for ordinary people so, let's wait for the exciting first images of the official mission.
Thank you for advising.

@sepmark yep, science data will start very early July! Then expect that it will take us several weeks to process data, so early fall/late summer is when you should start seeing the exciting science results!

@_astronoMay so exciting!!! I’m so looking forward to see pictures from JWST!! :ameowbongo:

@_astronoMay I'm excited. There's still so much to discover and explore out there.

And then there are people who state that everything that needs discovering is already discovered. Narrow!

@_astronoMay I have read that this goes beyond everyone's expectations and that it had already broke the record of the farthest object observed, a galaxy that's 19 billion light years away.


Hmm, I haven't heard about that! There were some galaxies that were in the background of a calibration image that was released, but very few people have the actual data that made up those images so no science on it has been done yet.

There was a recent discovery of the farthest star/galaxy ever observed with the Hubble Space Telescope and that target will be observed with JWST once science observations start, maybe that's what you're thinking of?

@_astronoMay I guess I mixed up things a bit 😅
Sorry for that, this was the news I saw. 😁

@paillp no worries! Completely understandable with all the exciting news coming out about both telescopes! Happy to have you here!

@_astronoMay this is amazing. I can't imagine the things we'll see.

@_astronoMay This is very impressive! 😀 Thanks for sharing 😊

What does the μm value represent? As JWT doesn't present a larger one, I assume that it's not related to resolution.

@MartinShadok that value is the wavelength of light being observed! All of these telescopes observe in the infrared and have multiple filters so we can look at only specific colors of light at a time

@_astronoMay Why do the stars have eight spokes, as if it’s got an eight-blade aperture?

@cormacrelf @_astronoMay My understanding that this is a result of the mirror not really being concave but many flat polygons which are each aligned to focus a bit of the light on the sensor resulting in artifacting!

@cyberspice @cormacrelf

yes, this has to do with the shape of the mirrors!

Since they're not a circle, a star won't look like a circle either. There's a lot of physics that goes into this, but here's an example of what stars would look like if observed with different shape mirrors, JWST is on the far right!

@_astronoMay @cyberspice ah! Now I look at it the eight spokes are suspiciously squashed. Very cool, thanks!

@_astronoMay @muffinista that’s so cool! do you have any insight into why the bright stars seem to have streaks around them in the JWST image? Is that some kind of focussing / aperture thing?

@halcy @muffinista

this has to do with the shape of the mirrors! Since it's not a circle, a star won't look like a circle. Here's an example of what a star would look like if observed with different shape mirrors:

A friend explained to me that broadly this is the impulse response of the optical systems transfer function and jesus, fourier and systems analysis really do show up everywhere don’t they

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