James Webb Telescope Updates

[Hans Blaster]

The full list of releases, with the full res images of all the pictures released today is located here:
Science Releases
All the future images releases will also be here, so if you're interested in future pictures, keep an eye on it!
That image of the Carina Nebula Halbhh shared is perhaps one of my favorite pictures of space ever taken. I can't stop looking at it. It's truly, utterly magnificent!


I know that for even the "continuous" observations, they do it in different segments. They way I've heard it described is that the photosensors are so sensitive, that they have to occasionally let them "rest" by blocking out the light to avoid damaging them. Then, they'll uncover them again, and take in more light.

Virtually all modern astronomical imaging sensors are CCDs or similar semi-conductor based pixelated detectors. They work by photons freeing electrons in a single detector element. To get the image out the pixels have to be read (counted) by the electronics. There is also a limit to how much charge can accumulate in a single detector element before the pixel becomes overfilled and doesn't detect new photons. (Oversaturation). When this happens you don't know how many photons actually hit that pixel, just a lower limit. The multiple exposures are generally to prevent that from happening. (They also "jitter" the image to avoid imprints from tiny variations in the detector, and fill in gaps between sub-detectors. Multiple sub-exposures also isolate the pixels "lit-up" by cosmic rays. Etc.)

And it seems that Webb can do some various bits of science blazingly fast - This spectrum only took about 4 and a half minutes of exposure!
https://twitter.com/astronomolly/status/1546865893254303744

At z=4.4!

 

[Green Sun]

A paper has been released by NASA, ESA, and CSA on the current status of JWST post-commissioning, with excellent news.

https://www.stsci.edu/files/live/si...documents/jwst-science-performance-report.pdf

[T]he science performance of JWST is better than expected. The optics are better aligned, the point spread function is sharper with higher encircled energy, and the optical performance is more time-stable than requirements. The fine guidance system points the observatory several times more accurately and precisely than required. The mirrors are cleaner than requirements, which translates into lower-than-expected levels of near-infrared stray light, meaning that the <5 μm sky background will be darker for JWST than expected. The science instruments have generally higher total system throughput than pre-launch expectations. Detector noise properties are similar to ground tests, albeit with higher rates of cosmic rays, as expected in deep space. Collectively, these factors translate into substantially better sensitivity for most instrument modes than was assumed in the exposure time calculator for Cycle 1 observation planning, in many cases by tens of percent. In most cases, JWST will go deeper faster than expected. In addition, JWST has enough propellant onboard to last at least 20 years.

 

[Halbhh]

A paper has been released by NASA, ESA, and CSA on the current status of JWST post-commissioning, with excellent news.

https://www.stsci.edu/files/live/si...documents/jwst-science-performance-report.pdf

that's quite good

 

[Halbhh]

Angular width of star field?

Bill Nelson, NASA

 

[loveofourlord]

Angular width of star field?

Bill Nelson, NASA

ahhh thanks, in a discussion over if those were stars or galaxies I realized YES they were stars, but brought up the question of how big of a patch of sky was it.

 

[Halbhh]

ahhh thanks, in a discussion over if those were stars or galaxies I realized YES they were stars, but brought up the question of how big of a patch of sky was it.

Yes, foreground stars and background very many galaxies. That we see so many galaxies in such a small angular width of field, it helps one visualize how the universe has so many.

 

[sjastro]

JWST reveals water in atmosphere of exoplanet WASP- 96b 1120 light years way.
Amazing.

JWST spectrum of WASP-96 b | The Planetary Society

 

[sjastro]

Comparison of Carina Nebula.

 

[loveofourlord]

Comparison of Carina Nebula.

Reminds me of when hubble did similar thing to pillars of creation

 

[Halbhh]

JWST reveals water in atmosphere of exoplanet WASP- 96b 1120 light years way.
Amazing.

View attachment 318242

JWST spectrum of WASP-96 b | The Planetary Society

Interestingly, I remember reading many years back a bit saying that water is believed to be the 2nd most abundant molecule in the Universe after the hydrogen molecule, and has been observationally found of course in every cool enough body in our solar system, in clouds of interstellar matter in abundance , and also in many various exoplanets observations. This has to do with how oxygen is one of the the most abundant heavier than helium products of supernovae. Let me see if I can find a nice article to lay out some about it.

Ah, I see that if you count an H3 as being another molecule (H2 being the most common molecule), then water would not be 2nd (and some views about other common molecules like HO and CO, etc. could put it down a little more), but it's super abundant. This is because oxygen is more abundant than carbon. I'll grab a reference or 2.

According to Chandra's data, the exploding star blasted off 10,000 Earth masses of sulphur; 20,000 Earth masses of silicon; 70,000 Earth masses of iron; and 1 million Earth masses of oxygen...
We Finally Know What Elements Are Contained in an Exploded Supernova

Relative elemental abundance in the Universe is thought to be:

1 Hydrogen 739,000
2 Helium 240,000
8 Oxygen 10,400
6 Carbon 4,600
10 Neon 1,340
Abundance of the chemical elements - Wikipedia

So, basically, expect to find at least some water in every planet except possibly (my speculation) some that are hot enough by being close enough to stars or with sufficient stellar wind in combination with radiation to have dissociated it and evaporated away the hydrogen (as Mars has experienced we think a lot of for example, but we find water on Mars simply underground and/or at the poles as ices, etc., as the planet is cool enough). Note that often the water would be vapor or ice, not liquid, but it's going to be everywhere cool enough in some form, pretty much.

But, it will still be news that many would like to hear, no doubt, that we found water in exoplanets (even though yet again as so many times already) in more observations today and soon.

I'd just like people to become aware it's in most every planet. (actually, to me, not finding it in a planet is more interesting than finding it because not finding any traces or only a tiny trace requires an explanation, and those are interesting explanations in themselves)

When we find methane, etc., organic compounds in explanets -- common molecules produced abiotically, and even including O2(!) -- I've...gotta feeling we are going to have to explain more than once or twice these don't require life or demonstrate life, but more evidence would be needed. I'd be delighted if we can find more convincing evidence than methane or molecular oxygen (which don't strongly indicate life) that a planet might have elementary life (like something akin to algae or whatever) -- that would be something.

 

[Halbhh]

Let's get ready for the inevitable claims and questions that will be coming sooner or later on the internet. Here's a prepper for O2 (breathable oxygen) found on an exoplanet:

Would the (interesting and encouraging) presence of free oxygen in an exoplanet atmosphere suggest strongly it has life?

Well, no... (even though it's pleasant to think about future colonies or such if you like future speculative fiction)

Oxygen on exoplanets isn't proof of life – Exoplanet Exploration: Planets Beyond our Solar System

 

[sjastro]

Element composition of a galaxy 13.1 billion light years away.
Note the emission spectrum has been redshifted into the infrared range due to expansion of the universe.

​

Webb spectrum showcases galaxy’s composition

 

[sjastro]

Interestingly, I remember reading many years back a bit saying that water is believed to be the 2nd most abundant molecule in the Universe after the hydrogen molecule, and has been observationally found of course in every cool enough body in our solar system, in clouds of interstellar matter in abundance , and also in many various exoplanets observations. This has to do with how oxygen is one of the the most abundant heavier than helium products of supernovae. Let me see if I can find a nice article to lay out some about it.

Ah, I see that if you count an H3 as being another molecule (H2 being the most common molecule), then water would not be 2nd (and some views about other common molecules like HO and CO, etc. could put it down a little more), but it's super abundant. This is because oxygen is more abundant than carbon. I'll grab a reference or 2.

According to Chandra's data, the exploding star blasted off 10,000 Earth masses of sulphur; 20,000 Earth masses of silicon; 70,000 Earth masses of iron; and 1 million Earth masses of oxygen...
We Finally Know What Elements Are Contained in an Exploded Supernova

Relative elemental abundance in the Universe is thought to be:

1 Hydrogen 739,000
2 Helium 240,000
8 Oxygen 10,400
6 Carbon 4,600
10 Neon 1,340
Abundance of the chemical elements - Wikipedia

So, basically, expect to find at least some water in every planet except possibly (my speculation) some that are hot enough by being close enough to stars or with sufficient stellar wind in combination with radiation to have dissociated it and evaporated away the hydrogen (as Mars has experienced we think a lot of for example, but we find water on Mars simply underground and/or at the poles as ices, etc., as the planet is cool enough). Note that often the water would be vapor or ice, not liquid, but it's going to be everywhere cool enough in some form, pretty much.

But, it will still be news that many would like to hear, no doubt, that we found water in exoplanets (even though yet again as so many times already) in more observations today and soon.

I'd just like people to become aware it's in most every planet. (actually, to me, not finding it in a planet is more interesting than finding it because not finding any traces or only a tiny trace requires an explanation, and those are interesting explanations in themselves)

When we find methane, etc., organic compounds in explanets -- common molecules produced abiotically, and even including O2(!) -- I've...gotta feeling we are going to have to explain more than once or twice these don't require life or demonstrate life, but more evidence would be needed. I'd be delighted if we can find more convincing evidence than methane or molecular oxygen (which don't strongly indicate life) that a planet might have elementary life (like something akin to algae or whatever) -- that would be something.

A preprint has come out recently that JWST has the spectral instrument capability of detecting CFCs on exoplanets orbiting Class M stars (not Class M planets re Star Trek!) which are dim enough not to drown out the signal.
The detection of CFCs might indicate an industrial level civilization.

The presence of chlorofluorocarbons (CFCs) in Earth's atmosphere is a direct result of technology. Ozone-depleting CFCs have been banned by most countries, but some CFCs have persistent in elevated concentrations due to their long stratospheric lifetimes. CFCs are effective greenhouse gases and could serve as a remotely detectable spectral signature of technology. Here we use a three-dimensional climate model and a synthetic spectrum generator to assess the detectability of CFC-11 and CFC-12 as a technosignature on exoplanets. We consider the case of TRAPPIST-1e as well as a habitable Earth-like planet around a 3300 K M-dwarf star, with CFC abundances ranging from one to five times present-day levels. Assuming an optimistic James Webb Space Telescope (JWST) Mid Infrared Instrument (MIRI) low resolution spectrometer (LRS) noise floor level of 10 ppm to multiple co-added observations, we find that spectral features potentially attributable to present or historic Earth-level CFC features could be detected with a SNR ≥3−5 on TRAPPIST-1e, if present, in ∼100 hours of in-transit time. However, applying a very conservative 50 ppm noise floor to co-added observations, even a 5x Earth-level CFC would not be detectable no matter the observation time. Such observations could be carried out simultaneously and at no additional cost with searches for biosignature gases. Non-detection would place upper limits on the CFC concentration. We find that with the launch of JWST, humanity may be approaching the cusp of being able to detect passive atmospheric technosignatures equal in strength to its own around the nearest stars.

https://arxiv.org/pdf/2202.05858.pdf

 

[loveofourlord]

Let's get ready for the inevitable claims and questions that will be coming sooner or later on the internet. Here's a prepper for O2 (breathable oxygen) found on an exoplanet:

Would the (interesting and encouraging) presence of free oxygen in an exoplanet atmosphere suggest strongly it has life?

Well, no... (even though it's pleasant to think about future colonies or such if you like future speculative fiction)

Oxygen on exoplanets isn't proof of life – Exoplanet Exploration: Planets Beyond our Solar System

Isn't it one of the first things to look for, but they then will look for other possible signs that would go with it? Especially if close enough look at it with radio signals.

 

[Hans Blaster]

A preprint has come out recently that JWST has the spectral instrument capability of detecting CFCs on exoplanets orbiting Class M stars (not Class M planets re Star Trek!) which are dim enough not to drown out the signal.
The detection of CFCs might indicate an industrial level civilization.

If the have CFCs it probably is a Class M planet orbiting an M dwarf star.

 

[Hans Blaster]

Element composition of a galaxy 13.1 billion light years away.
Note the emission spectrum has been redshifted into the infrared range due to expansion of the universe.

​

Webb spectrum showcases galaxy’s composition

It really bugs me when they won't quote the redshift. So I tried to figure it out myself...

The oxygen lines look like the forbidden pair of [O III] lines near 5000 A, which would make the adjacent hydrogen line the Balmer-beta line (with gamma, delta, and epsilon to the blue) and a redshift of z=8.4.

Again, z=8.4 is quite impressive and the composition of the hot, ionized interstellar gas should be fairly easy to determine (at z=8.4).

 

[Halbhh]

A preprint has come out recently that JWST has the spectral instrument capability of detecting CFCs on exoplanets orbiting Class M stars (not Class M planets re Star Trek!) which are dim enough not to drown out the signal.
The detection of CFCs might indicate an industrial level civilization.

https://arxiv.org/pdf/2202.05858.pdf

Very interesting. I hope that can be extended to non M class stars. Red dwarfs have been found generally to flare with intensity similar (as much or more than) to even our own sun which is putting out far more energy, and so that flaring of these little red stars is a severe problem for having life similar to like we know it here on Earth, due to that flaring (and the stellar wind) degrading the atmospheres of planets close enough to the dim red stars to have liquid water, and irradiating them also more intensely (as that goes by the square of distance). Basically the liquid water zone is on the order 10 times closer to the little red stars see, meaning such radiation like UV from flares similar to much larger stars like our sun would then for example sometimes have an intensity of 100 times more intense when a planet is 10 times closer, requiring a thicker atmosphere to block it at least from life like bacteria that could not handle that UV, etc., but that's where the problem of the red dwarf stellar wind and flares tend to remove atmosphere from the relatively much nearer planets. So, hand waving, but you get the idea. Such planets would have to get through a much more stringent narrow door than Earth it would seem in terms of producing atmosphere and having an exceptionally strong magnetic field to help shield the atmosphere from the stellar wind, and so on.

 

[Halbhh]

Isn't it one of the first things to look for, but they then will look for other possible signs that would go with it? Especially if close enough look at it with radio signals.

Well for radio signals that searching has been ongoing for decades already, the SETI type searching.

What's going to be new observations here is much more about various chemical signatures in the new atmospheric spectra Webb will see. There are of course already ideas about what to look for in the coming new atmospheric spectra, and along with those it seems possible there will also be unexpected abundances of various molecules (or that's likely is my guess, but my background isn't in chemistry, and I've only the modest amount of information from various atmospheric observations from other telescopes and past explanations of those on a summary level). But we could reasonably expect relative abundances of some substances to be different than hypothesized, and that will be interesting and lead to plenty of new hypotheses/theories. It often takes months to see new theories, unless one has already in the works. So, in that case, in time sooner or later we would then see new theories and papers would come out speculating or calculating models about how such relative abundances of various molecules could be present, and more than one view, competing theories. Before the new theories arrive, plenty of speculations will be around.

 

[loveofourlord]

Well for radio signals that searching has been ongoing for decades already, the SETI type searching.

What's going to be new observations here is much more about various chemical signatures in the new atmospheric spectra Webb will see. There are of course already ideas about what to look for in the coming new atmospheric spectra, and along with those it seems possible there will also be unexpected abundances of various molecules (or that's likely is my guess, but my background isn't in chemistry, and I've only the modest amount of information from various atmospheric observations from other telescopes and past explanations of those on a summary level). But we could reasonably expect relative abundances of some substances to be different than hypothesized, and that will be interesting and lead to plenty of new hypotheses/theories. It often takes months to see new theories, unless one has already in the works. So, in that case, in time sooner or later we would then see new theories and papers would come out speculating or calculating models about how such relative abundances of various molecules could be present, and more than one view, competing theories. Before the new theories arrive, plenty of speculations will be around.

and of course the biggest weakness is, were only looking for life based on what we have, what would silicon based life or such look like in a the same thing.

As for signal, well we are with SETI, but having a broad search wich hasn't even examined a few % of the night sky, yes we've been looking for a while, but the sky is massive heh. Plus were not looking for alien signals, as much as alien carrier signals. I remember the discussion over the 'dyson' swarm that if it did turn out to be something like that, we would have to develop a radio telescope to be able to pick anything up due to how faint the signal most likely would be.

 

[loveofourlord]

my response to the issue of lack of signals is, we can really only look for Radio signals, if there is more advanced communications especially anything faster then light, we would have a hard enough time detecting let alone knowing how to read.