James Webb Space Telescope, information, updates and discussion Options

[StargazeInWonder]

Uranus, Neptune, and the uranian satellites will indeed be studied by JWST soon/already. I don't notice Triton being mentioned, but maybe it's hidden in another proposal, or maybe it didn't make the cut for Cycle 1; it's certainly a worthy target that wouldn't be ignored indefinitely.

https://www.stsci.edu/jwst/science-executio...rams/cycle-1-go

https://www.stsci.edu/jwst/science-executio...on.html?id=1585
https://www.stsci.edu/jwst/science-executio...on.html?id=1598
https://www.stsci.edu/jwst/phase2-public/1786.pdf

I would expect some outstanding science to result. To some extent, we won't know what spectroscopy in JWST's wavelengths is capable of until we get the first results, but the potential is excellent.

[hendric]

Unless you deliberately blurred the images, this kind of simulation always massively overestimates how many details you would really be able to see. Just FYI.

Right, because the shrunk pixels don't get affected by the PSF of the telescope? Here's one with a 5 pixel Gaussian applied.



Pluto is a target in the first Observing Cycle with a program lead by Emmanuel Lellouch so we'll know in about a year I'd say?

https://www.stsci.edu/jwst/science-executio...on.html?id=1658

[blueaeshna]

JWST images the Phantom Galaxy M74 Webb inspects the heart of the Phantom Galaxy

[Bill Harris]

In the M74 views there is a circular cavity in the dust and gas at all wavelengths, visible at about the 7:00 position angle. Has there been any comment about that, or is it just a random coincidence in the distribution?

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[StargazeInWonder]

I would guess that a large supernova took place at the center of that region long ago. We have something like that close to us, the Veil Nebula, which is not visible to the naked eye but is a whopping 3° of arc in diameter (6 full Moons wide).

There are still plenty of stars inside that volume. If the supernova interpretation is correct, it would be like a wind that blew dust and certain gas out to the edge, but of course have no perceptible force on dense things like stars.

[pac56]

Interesting interview of Scott Acton on the commissioning of the telescope (wavefront sensing): https://spectrum.ieee.org/james-webb-space-telescope-mirror

[Bill Harris]

First Webb image of Mars:

https://www.newscientist.com/article/233851...ctures-of-mars/

Re: image at top of article: "while the longer wavelength image reveals information about heat emitted from the Martian surface and atmosphere, as well as the concentrations of carbon dioxide in the atmosphere (bottom right, above)."

Note that the Hellas Basin (lower left of the lower right) shows up darker, which is "cooler", but i would have expected that low elevation area to be warmer. But i wonder if the thicker column of atmosphere (CO2) would have an effect?

---Bill

[mcaplinger]

Note that the Hellas Basin (lower left of the lower right) shows up darker, which is "cooler", but i would have expected that low elevation area to be warmer. But i wonder if the thicker column of atmosphere (CO2) would have an effect?

Better unpaywalled link is https://www.esa.int/Science_Exploration/Spa...s_of_Red_Planet

4.3 microns is not quite thermal IR, and there is an CO2 absorption there, so I would guess the 4.3 micron signal is correlated to elevation at least in part.

Seems odd that they didn't show the same FOV between the two wavelengths.

[Bill Harris]

Thanks, Mike. That is a much better link. This initial Webb Data Dribble frequently has loose ends and we may get better data later.
Still, these are a wonderful preview of incredible images and data to come.

--Bill

[StargazeInWonder]

This release describes the darker appearance of Hellas in detail. In a phrase, "higher pressure leads to a suppression of the thermal emission at this particular wavelength range."

https://blogs.nasa.gov/webb/2022/09/19/mars...-of-red-planet/

[Bill Harris]

First Webb imagery of Neptune:

https://webbtelescope.org/contents/news-rel...46#section-id-2

[Bill Harris]

Just for reference, here are images from the VLT and Hubble. Of interest is the storm system shown with white clouds. And note that Webb is imaging in infrared wavelengths and is looking at things differently.

--Bill

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[Ian R]

I'd wondered why the ring arcs aren't visible, but assuming models 2 and 3 are on the money (#2: 820.1118 deg/day & #3: 820.1121 deg/day), the arcs are obscured by Neptune's disc.

Obs time: 2022-07-12 06:52:35

[Bill Harris]

Ian, remember this is a NIR view of Neptune, and the rings/ring arcs may look different at those wavelenghts. I've not noticed anything more on this.

--Bill

[StargazeInWonder]

On Europa and Enceladus, which will be studied for plume signatures, for the first of certainly more than one time, in November and December:

I'm curious about JWST's ability to identify the signature of complex organics, and how calibration work would even be performed to determine their spectra. With a somewhat unconstrained number of possible organic compounds to look for, that seems like a lot of laboratory work involving unusual conditions to develop a catalog of reference spectra. This would seem like a need that has perhaps never existed before, but will be needed for interpreting JWST spectra of many objects, including Titan, comets, nebulae, exoplanet atmospheres, protoplanetary discs, and maybe more.

One may think of Europa's and Enceladus's plumes as two more "exo"planet atmospheres for JWST to study. It's interesting to note that JWST will provide a kind of data that even missions that visit those worlds will not. Maybe we'll see the spectra published in 2023, but understanding them seems like it could be a long game.