The James Webb Space Telescope

[pinball1970]

Brilliant!

They need a new graphic now though.

Otherwise we will just sit at “stage 7 complete” for the next two months.

That would be such a cruel irony, (considering how smoothly the progress has been so far) they They must be planning some type of sideshow.

NASA graphics have made small changes https://webb.nasa.gov/content/webbLaunch/whereIsWebb.html

Smallish. This is NASA though, I will take it.

Today

Last week

 

[Oldman too]

I had no need to worry.

I know, I just want to be able to say that after science operations begins. An amazing job so far though.

They have pushed back the curser on the progress line, we are now only 84% of the way along whereas last week we were at 98%.

I guess that's one way to define progress.

 

[pinball1970]

I know, I just want to be able to say that after science operations begins. An amazing job so far though.I guess that's one way to define progress.

I was being a tad facetious. Obviously everything has gone like clock work so far and that's great. However since we cannot see it and we are not getting images (besides those few cool images) it's nice to see each milestone pass successfully and the next few goals.
Let's see what they do.

 

[phyzguy]

Have you seen this image? How's that for progress??!

 

[Ibix]

That's a bit misleading - WISE is actually younger (2009/10) than Spitzer (2003). It just had a smaller primary mirror (40cm vs Spitzer's 85cm, if Wikipedia is to be believed), presumably because WISE was a sky survey instrument.

Webb, of course, has a 6.5m main mirror.

 

[valenumr]

Have you seen this image? How's that for progress??!View attachment 300975

Amazing! Tremendously amazing!

 

[Hornbein]

I guess that's one way to define progress.

It is a computer science tradition. The progress bar chugs along until it gets to 95% then freezes.

 

[pinball1970]

Have you seen this image? How's that for progress??!View attachment 300975

That's a bit misleading - WISE is actually younger (2009/10) than Spitzer (2003). It just had a smaller primary mirror (40cm vs Spitzer's 85cm, if Wikipedia is to be believed), presumably because WISE was a sky survey instrument.

Webb, of course, has a 6.5m main mirror.

I saw those images on youtube and was sceptical as I do not know enough about the technology to judge if the comparison was fair or not.

The first image on WISE looks like its pixels have been blown up. So it would look blurred compared to the other two.

I found this discussion.

https://www.universetoday.com/15568...compare-webb-to-other-infrared-observatories/

 

[Ibix]

The first image on WISE looks like its pixels have been blown up. So it would look blurred compared to the other two.

You'd pick your pixel size to match the telescope resolution, so the smaller telescopes would have fewer pixels in an image of the same region of sky. There's no point in spending lots of money getting a super fine grid on a big blur, and you'd get fewer photons per pixel into the bargain. So the size of the blobs of light is a function of the optics, and the size of the pixels is a function of how big you calculate the blobs are going to be. Notice that the biggest blob just above the center of the image is ~10 pixels across in both the WISE and Spitzer images.

 

[Oldman too]

https://blogs.nasa.gov/webb/wp-content/uploads/sites/326/2022/05/spitzer_vs_webb_LMC.gif

https://blogs.nasa.gov/webb/2022/05/09/miris-sharper-view-hints-at-new-possibilities-for-science/

NASA media presentation on JWST progress, 11:00 EST. Audio only.

 

[pinball1970]

https://blogs.nasa.gov/webb/wp-content/uploads/sites/326/2022/05/spitzer_vs_webb_LMC.gif

https://blogs.nasa.gov/webb/2022/05/09/miris-sharper-view-hints-at-new-possibilities-for-science/

NASA media presentation on JWST progress, 11:00 EST. Audio only.

They have illustrated on the site also.

https://webb.nasa.gov/content/webbLaunch/whereIsWebb.html

 

[pinball1970]

All the numbers are now the same brightness. So not greyed out.

There is the big tick too, I love the big tick! The press conference said the number of checks now out of 1000s was now at 200 or so but that was on the 9th May.

 

[Oldman too]

More space filler, interesting reading though.
https://blogs.nasa.gov/webb/2022/05...scovery-webbs-final-commissioning-activities/

 

[pinball1970]

More space filler, interesting reading though.
https://blogs.nasa.gov/webb/2022/05...scovery-webbs-final-commissioning-activities/

Those 17 modes tie in with those headers on the 4 instruments. 5 for NIRCam and 4 each for the rest. It looks complete on the graphic. Edit, checkout ≠sign off presumably. They get a gold ring.

 

[Oldman too]

Interesting links on first studies here, This could rightly be called "the greatest show off earth".
https://www.stsci.edu/contents/news...cience-program-activities-and-deliveries.html

https://arxiv.org/abs/2201.05112
Draft version pdf: https://arxiv.org/pdf/2201.05112.pdf

https://pdrs4all.org/

Cheers, Scott.

Edit 6/1: July 12th will first images release date.
https://www.nasa.gov/feature/goddard/2022/first-images-from-nasa-s-webb-space-telescope-coming-soon

https://jwst.nasa.gov/content/webbLaunch/deploymentExplorer.html

 

[pinball1970]

Interesting links on first studies here, This could rightly be called "the greatest show off earth"
Edit 6/1: July 12th will first images release date.
https://www.nasa.gov/feature/goddard/2022/first-images-from-nasa-s-webb-space-telescope-coming-soon

https://jwst.nasa.gov/content/webbLaunch/deploymentExplorer.html

Count down link. 38 days and counting!

https://www.jwst.nasa.gov/content/webbLaunch/countdown.html

 

[mfb]

The instrument checkout page has a first completed item, images with NIRCam.

There are rumors that 55 Cancri might be one of the first, or even the first, target. It has five known exoplanets, the innermost orbits the star in less than a day.

 

[pinball1970]

On the where is Webb? page that has been linked multiple times.Deployable Tower Assembly is in progress.

I have tried Where's Webb from 6.30am BST till now. It never fails on my desk top and never mid week. Can you access?
Edit. Where's Webb is back. Normal. Nominal.

 

[mfb]

NIRISS now has "Imaging (parallel only)" as completed step.

One mirror segment was hit by a larger than expected micrometeoroid. The impact on data-taking is likely small but they are still studying it.

 

[pinball1970]

NIRISS now has "Imaging (parallel only)" as completed step.

One mirror segment was hit by a larger than expected micrometeoroid. The impact on data-taking is likely small but they are still studying it.

This is a from DEC 2017

https://www.nasa.gov/feature/goddar...-about-the-toughness-of-nasa-s-webb-telescope

“Q: Once Webb is in orbit, how susceptible will it be to micrometeoroid strikes? For example, what would happen if one of Webb’s primary mirror segments or the sunshield got struck?

Paul: Although space is mostly empty, there is some debris. In the inner Solar System where Webb will orbit, we have a good understanding of what the population of meteoroids is like from years of observations and research. It’s mostly dust and very small particles, with the majority being sparsely distributed and tinier than grains of sand. There are some pebbles, rocks, and boulders, but they are very sparse and very rare. At Webb’s orbit at L2, the debris is all natural and the environment is not as hazardous as it is much closer to Earth, where there is a fair amount of human-generated “space junk.”

We know Webb will get struck by micrometeoroids during its lifetime, and we have taken that into account in its design and construction. We sized Webb’s main mirror so that even after years of little impacts it will still have the reflective surface area and quality necessary to do the science. We even did tests on the ground that emulated micrometeoroid impacts to demonstrate what will happen to the mirrors in space.

Similarly, part of the reason the sunshield has five layers is so it can tolerate more than the number of expected small holes, and even some tears, and still work as it should.
Also, almost all of Webb’s sensitive components (besides the mirrors and sunshield) are protected behind “micrometeoroid armor.” When micrometeoroids do strike, most are so small that they totally disintegrate upon impact, even when they hit something thin like thermal blankets or a sunshield membrane. Critical wires and electronics are shielded behind even more robust metal “armor” or inside metal boxes.”So when you say, “larger than expected” you mean from the data they had on the environment at L2 prior to launch?

The site was down for a while, any connection? Or was that just to update the instrument completion?

 

[Motore]

All spacecraft are expected to experience and designed to withstand micrometeoroid impacts, and JWST is no different. The observatory's engineers even subjected mirror samples to real impacts to understand how such events might affect the mission's science.

However, the recent impact was larger than those that mission personnel had modeled or could test on the ground, according to the statement.

from the link provided by @mfb

 

[pinball1970]

from the link provided by @mfb

165 days since launch, 33 days till first image I was just hoping the words meteor/micrometeoroid would not feature significantly on the thread before July 12th.

 

[pinball1970]

Better news, A few more signed off yesterday.

 

[Oldman too]

An early contender for observation time, the "Next Generation Deep Extragalactic Exploratory Public" will build on Hubble's deep field observations. The "P.I." is a Hubble Fellow with plenty of experience in Deep Field, high redshift work.
From the news release: https://webbtelescope.org/contents/news-releases/2022/news-2022-015.html
(“We’re using two science instruments at once, and they will observe continuously.” They will point Webb’s Near-Infrared Imager and Slitless Spectrograph (NIRISS) on the primary Hubble Ultra Deep Field, and Webb’s Near-Infrared Camera (NIRCam) on the parallel field, getting twice the bang for their “buck” of telescope time.)

Principal Investigator, Prof. S. Finkelstein
NGDEEP Proposal #2079 Cycle: 1, GO
https://www.stsci.edu/jwst/phase2-public/2079.pdf

An overview from the above pdf.
"We propose NGDEEP: The Webb Deep Extragalactic Exploratory Public Survey. NGDEEP leverages efficient parallel observations over 121.7 hr with NIRISS in the Hubble Ultra Deep Field (HUDF) and NIRCam in the HUDF-Par2 field to constrain the physical processes dominating feedback in galaxies from z~1-12. Observing with JWST in the HUDFs leverages off the deepest optical imaging from Hubble and makes NGDEEP a premier legacy field for both missions.

NGDEEP observes deeply with NIRISS (60-190 ks) to detect faint emission lines (~ 10^-18 cgs) for >1000 mostly low-mass (log M/Msol = 7-9) galaxies. NGDEEP-NIRISS will enable robust constraints on the low-mass end of the mass-metallicity relation and constrain stochastic star-formation by probing H-alpha based star-formation rates to 0.1 Msol/yr in these low-mass galaxies. These measurements will limit chemical enrichment and feedback physical prescriptions in models, which are currently unconstrained at these masses.

In parallel, NGDEEP will obtain the deepest 6-band NIRCam imaging (m~30.6-30.9) on the HUDF-Par2 field. NGDEEP-NIRCam will probe z > 12, and constrain stellar feedback prescriptions in models by precisely measuring the shape of the faint-end of the UV luminosity function at z~10. These data will provide unprecedented morphological detail in galaxies at all redshifts, and reconnoiter the sites of first black hole formation.

Being public immediately, NGDEEP follows in the footsteps of the Hubble deep field programs, enabling the community to explore the power of Webb when pushed to its limits. As a treasury program, we are committed to the rapid reduction and release of high-quality reduced data products and catalogs."

 

[Filip Larsen]

Almost there. It appears that we should be ready to become teary eyed on July 12th ...
https://arstechnica.com/science/202...dinary-images-captured-by-its-webb-telescope/

 

[pinball1970]

Almost there. It appears that we should be ready to become teary eyed on July 12th ...
https://arstechnica.com/science/202...dinary-images-captured-by-its-webb-telescope/

Yes Just two modes to sign off and If the NASA scientists are overcome with emotion at this stage then we should buckle in!
The “our beautiful universe” community will probably go nuts, be great some feedback from them on the 12th

 

[Oldman too]

Hubble is working out to be a fine spotting scope, a new target for WEBB to be sure.

https://www.science.org/content/art...niverse-s-first-stars-quickly-coalesced-disks
"The galaxy, called MACS1149-JD1 or just JD1 for short, is not the most distant known, but it is now the most distant galaxy with anything known about its dynamics."

 

[Borg]

One instrument package left and just a little over a week to go.
https://jwst.nasa.gov/content/webbLaunch/countdown.html

 

[Filip Larsen]

https://blogs.nasa.gov/webb/2022/07/06/webbs-fine-guidance-sensor-provides-a-preview/

 

[pinball1970]

https://blogs.nasa.gov/webb/2022/07/06/webbs-fine-guidance-sensor-provides-a-preview/

I wondered about the black hole Suns!

". In addition, the centers of bright stars appear black because they saturate Webb’s detectors, and the pointing of the telescope didn’t change over the exposures to capture the center from different pixels within the camera’s detectors"

 

[collinsmark]

I wondered about the black hole Suns!

". In addition, the centers of bright stars appear black because they saturate Webb’s detectors, and the pointing of the telescope didn’t change over the exposures to capture the center from different pixels within the camera’s detectors"

Yeah, this is not an uncommon convention in astrophotography software (e.g., FITS viewers), particularly for use in quick-and-dirty viewing of the data. Saturated pixels are often displayed as black to let the astronomer know quickly (due to the inevitable high contrast) that saturation has occurred. It's not universal though -- it's just a convention -- and depends on the software. [It doesn't change the underlying data; rather it's just a matter of how the data is displayed.]

The same thing is often done on high-end terrestrial cameras too. So it's not limited to astronomy. Many high-end cameras (Nikon, Canon, etc.) will have a mode such that preview and display on the back of the camera will go black (or some predefined color [or pattern]) for regions where saturation occurs. It's a way of the camera telling the photographer, "Ah, hell. Looky-here, you've gone done blown the highlights again, you bastard."

 

[Oldman too]

A list of first image targets, compliments of NASA/JPL.
https://www.jpl.nasa.gov/news/nasa-shares-list-of-cosmic-targets-for-webb-telescopes-first-images?

Carina Nebula: The Carina Nebula is one of the largest and brightest nebulae in the sky, located approximately 7,600 light-years away in the southern constellation Carina. Nebulae are stellar nurseries where stars form. The Carina Nebula is home to many massive stars several times larger than the Sun.

WASP-96b (spectrum): WASP-96b is a giant planet outside our solar system, composed mainly of gas. The planet, located nearly 1,150 light-years from Earth, orbits its star every 3.4 days. It has about half the mass of Jupiter, and its discovery was announced in 2014.

Southern Ring Nebula: The Southern Ring, or “Eight-Burst” nebula, is a planetary nebula – an expanding cloud of gas surrounding a dying star. It is nearly half a light-year in diameter and is located approximately 2,000 light-years away from Earth.

Stephan’s Quintet: About 290 million light-years away, Stephan’s Quintet is located in the constellation Pegasus. It is notable for being the first compact galaxy group ever discovered in 1787. Four of the five galaxies within the quintet are locked in a cosmic dance of repeated close encounters.

SMACS 0723: Massive foreground galaxy clusters magnify and distort the light of objects behind them, permitting a deep field view into both the extremely distant and intrinsically faint galaxy populations.

 

[pinball1970]

What's this thing tonight? With Joe Biden? They are releasing one image?
@mfb @collinsmark @Oldman too
I posted a screen grab today and did not even notice the Biden date. On Random thoughts.

 

[Oldman too]

What's this thing tonight? With Joe Biden? They are releasing one image?

I saw your screen grab, didn't notice the fine print about today though, thanks for pointing out the "reveal".

 

[Devin-M]

Does anyone know whether it would be possible to estimate the temperature of an object via a single narrowband observation? Suppose the F323N filter was used while NIRCam targeted an asteroid. Only 3.2 micron light can reach the imaging sensor. How would I derive the temperature of the asteroid from this single observation?

https://jwst-docs.stsci.edu/jwst-ne...cam-filters#NIRCamFilters-Filtertransmissions

 

[pinball1970]

Does anyone know whether it would be possible to estimate the temperature of an object via a single narrowband observation? Suppose the F323N filter was used while NIRCam targeted an asteroid. Only 3.2 micron light can reach the imaging sensor. How would I derive the temperature of the asteroid from this single observation?

View attachment 304009

https://jwst-docs.stsci.edu/jwst-ne...cam-filters#NIRCamFilters-Filtertransmissions

I think they could have a good go at that

 

[berkeman]

What's this thing tonight? With Joe Biden? They are releasing one image?
@mfb @collinsmark @Oldman too

Yeah, what the heck does Biden have to do with a NASA release? And the news articles say it would happen at 5:30PM US Eastern Time, which was an hour ago and no images anywhere that I can find so far...

 

[Devin-M]

https://www.nasa.gov/webbfirstimages

 

[berkeman]

Thank you very much, Devin. Is the color scheme that you showed in the plot above in your post #285 a standard for coloring the IR images from Webb?

 

[phinds]

I'm completely puzzled. The statement, on the NASA web site, about the age of the galaxies in the image says

The image shows the galaxy cluster SMACS 0723 as it appeared 4.6 billion years ago.

Given that the Hubble has imaged galaxies at about 13.4 billion years old, what's the big deal w/ 4.6 billion years old? The Webb image does not appear to me to be any more clear than the Hubble Deep Field,

 

[berkeman]

I'm completely puzzled. The statement, on the NASA web site, about the age of the galaxies in the image says

Given that the Hubble has imaged galaxies at about 13.4 billion years old, what's the big deal w/ 4.6 billion years old?

It looks like another metric/Imperial units conversion issue...

 

[JLowe]

I think SMACS is a bit more in the foreground, magnifying galaxies behind it that are apparently deeper and sharper than the Hubble deep field images.

 

[dlgoff]

Yeah, what the heck does Biden have to do with a NASA release? And the news articles say it would happen at 5:30PM US Eastern Time, which was an hour ago and no images anywhere that I can find so far...

I saw this on the TV news this evening.

From: https://www.houstonchronicle.com/ne...ases-first-image-from-James-Webb-17297915.php

President Joe Biden released the first image from the James Webb Space Telescope on Monday, revealing what NASA called a "glimpse" into 13.5 billion years of cosmic history.

 

[russ_watters]

I'm completely puzzled. The statement, on the NASA web site, about the age of the galaxies in the image says

View attachment 304021
Given that the Hubble has imaged galaxies at about 13.4 billion years old, what's the big deal w/ 4.6 billion years old?

Typo substituting age of our sun for age of the universe?

The Webb image does not appear to me to be any more clear than the Hubble Deep Field

Here's a side-by-side with a Hubble photo of the same cluster:

 

[fresh_42]

I'm completely puzzled. The statement, on the NASA web site, about the age of the galaxies in the image says

View attachment 304021
Given that the Hubble has imaged galaxies at about 13.4 billion years old, what's the big deal w/ 4.6 billion years old? The Webb image does not appear to me to be any more clear than the Hubble Deep Field,

Here is a comparison:
https://www.sciencealert.com/breaki...e-universe-ever-is-here-and-it-s-breathtaking

Hubble:

Webb:

 

[fresh_42]

Typo substituting age of our sun for age of the universe?

Here's a side-by-side with a Hubble photo of the same cluster:

It is about what's behind the cluster.

 

[Vanadium 50]

Be aware that the Webb pictures are in false color.

 

[Devin-M]

 

[Jarvis323]

I'm completely puzzled. The statement, on the NASA web site, about the age of the galaxies in the image says

View attachment 304021
Given that the Hubble has imaged galaxies at about 13.4 billion years old, what's the big deal w/ 4.6 billion years old? The Webb image does not appear to me to be any more clear than the Hubble Deep Field,

It looks like another metric/Imperial units conversion issue...

Typo substituting age of our sun for age of the universe?

4.6 billion years is the age of the light that the telescope collected, based on the distance, hence "as it appeared ...".

 

[Filip Larsen]

The Ars technica story on this first image includes a link to the full image I haven't noticed in any of the other references mentioned (or I may simply have missed it):
https://stsci-opo.org/STScI-01G7JJADTH90FR98AKKJFKSS0B.png