James Webb

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BaldEagle
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James Webb

Post by BaldEagle » Thu Dec 12, 2019 1:35 am

Aside from looking deeper into space, what new revelations should we expect to see with the James Webb?

Will the Webb take us further toward the big bang and fine-tuning of the age of the Universe? If so, how far into the beginning of spacetime?

What will the various filtering show us? Will we be able to see into the center of galaxies?

Will the Webb allow us to see deeper into our own Milky Way galaxy?

How much improved detail can we expect viewing galaxies? Individual stars? And/or planets?

Thank you.

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orin stepanek
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Re: James Webb

Post by orin stepanek » Thu Dec 12, 2019 3:25 am

BaldEagle wrote:
Thu Dec 12, 2019 1:35 am
Aside from looking deeper into space, what new revelations should we expect to see with the James Webb?

Will the Webb take us further toward the big bang and fine-tuning of the age of the Universe? If so, how far into the beginning of spacetime?

What will the various filtering show us? Will we be able to see into the center of galaxies?

Will the Webb allow us to see deeper into our own Milky Way galaxy?

How much improved detail can we expect viewing galaxies? Individual stars? And/or planets?

Thank you.
I'm really excited about the James Webb; and I wish it was in orbit already! I think it will really open up the nearby universe to really great knowledge of the neighboring stars as well as deep space!
Orin

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Re: James Webb

Post by neufer » Thu Dec 12, 2019 12:55 pm

.
Of all the Asterisk Cafes, in all the towns, in all the world, BaldEagle walks into mine…
BaldEagle wrote:
Thu Dec 12, 2019 1:35 am

Aside from looking deeper into space, what new revelations should we expect to see with the James Webb?

Will the Webb take us further toward the big bang and fine-tuning of the age of the Universe? If so, how far into the beginning of spacetime?

What will the various filtering show us? Will we be able to see into the center of galaxies?

Will the Webb allow us to see deeper into our own Milky Way galaxy?

How much improved detail can we expect viewing galaxies? Individual stars? And/or planets?
I heard those questions once — as a matter of fact, I’ve heard a lot of questions in my time.
They began with the sound of a tinny piano playing in a parlor downstairs…”

orin stepanek wrote:
Thu Dec 12, 2019 3:25 am

I'm really excited about the James Webb; and I wish it was in orbit already! I think it will really open up the nearby universe to really great knowledge of the neighboring stars as well as deep space!
And if, perchance, JWST never becomes operational...we’ll always have Hubble.
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orin stepanek
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Re: James Webb

Post by orin stepanek » Thu Dec 12, 2019 8:11 pm

neufer wrote:
Thu Dec 12, 2019 12:55 pm
.

orin stepanek wrote:
Thu Dec 12, 2019 3:25 am

I'm really excited about the James Webb; and I wish it was in orbit already! I think it will really open up the nearby universe to really great knowledge of the neighboring stars as well as deep space!
And if, perchance, JWST never becomes operational...we’ll always have Hubble.
I hope that doesn't happen! Isn't that a reason it's taking as long to git it up? To make sure everything is going to go as planed?🤞
Orin

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neufer
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Re: James Webb

Post by neufer » Fri Dec 13, 2019 2:59 am

orin stepanek wrote:
Thu Dec 12, 2019 8:11 pm
neufer wrote:
Thu Dec 12, 2019 12:55 pm
orin stepanek wrote:
Thu Dec 12, 2019 3:25 am

I'm really excited about the James Webb; and I wish it was in orbit already! I think it will really open up the nearby universe to really great knowledge of the neighboring stars as well as deep space!
And if, perchance, JWST never becomes operational...we’ll always have Hubble.
I hope that doesn't happen! Isn't that a reason it's taking as long to git it up?
To make sure everything is going to go as planed?🤞
  • The curse of Hubble:
https://en.wikipedia.org/wiki/Hubble_Space_Telescope wrote:
<<The JWST has a history of major cost overruns and delays which have resulted in part from outside factors such as delays in deciding on a launch vehicle and adding extra funding for contingencies. By 2006, $1 billion had been spent on developing JWST, with the budget at about $4.5 billion at that time. A 2006 article in the journal Nature noted a study in 1984 by the Space Science Board, which estimated that a next generation infrared observatory would cost $4 billion (about $7 billion in 2006 dollars). By October 2019, the estimated cost of the project had reached $10 billion for launch in 2021.>>
https://en.wikipedia.org/wiki/Hubble_Space_Telescope wrote:
<<By early 1986, the planned HST launch date of October that year looked feasible, but the Challenger accident brought the U.S. space program to a halt, grounding the Space Shuttle fleet and forcing the launch of Hubble to be postponed for several years. The telescope had to be kept in a clean room, powered up and purged with nitrogen, until a launch could be rescheduled. This costly situation (about US$6 million per month) pushed the overall costs of the project even higher. Furthermore, the ground software needed to control Hubble was not ready in 1986, and was barely ready by the 1990 launch.

Eventually, following the resumption of shuttle flights in 1988, the launch of the telescope was scheduled for 1990. On April 24, 1990, Space Shuttle Discovery successfully launched the telescope into its planned orbit during the STS-31 mission. From its original total cost estimate of about US$400 million, the telescope cost about US$4.7 billion by the time of its launch. Hubble's cumulative costs were estimated to be about US$10 billion in 2010, twenty years after launch.

Within weeks of the launch of the telescope, the returned images indicated a serious problem with the optical system. Although the first images appeared to be sharper than those of ground-based telescopes, Hubble failed to achieve a final sharp focus and the best image quality obtained was drastically lower than expected. Images of point sources spread out over a radius of more than one arcsecond, instead of having a point spread function (PSF) concentrated within a circle 0.1 arcsec in diameter, as had been specified in the design criteria.

Analysis of the flawed images revealed that the primary mirror had been polished to the wrong shape. Although it was probably the most precisely figured optical mirror ever made, smooth to about 10 nm (0.4 μin), the outer perimeter was too flat by about 2,200 nm. This difference was catastrophic, introducing severe spherical aberration, a flaw in which light reflecting off the edge of a mirror focuses on a different point from the light reflecting off its center.>>
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Re: James Webb

Post by TerribleTadpole » Tue Jun 22, 2021 6:06 am

A friend of mine wondered whether we might be able to link observations from multiple orbital observatories using long-baseline-interferometry like we do on the ground. I suspect that it is much more difficult in space where the separation between the stations is not fixed, and where they are all moving independently with respect to the subject. But I thought it worth asking the question. The longer baselines available from space, and the lack of obstacles would seem to be advantages.

Is anyone aware of research on this idea?

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Chris Peterson
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Re: James Webb

Post by Chris Peterson » Tue Jun 22, 2021 1:33 pm

TerribleTadpole wrote:
Tue Jun 22, 2021 6:06 am
A friend of mine wondered whether we might be able to link observations from multiple orbital observatories using long-baseline-interferometry like we do on the ground. I suspect that it is much more difficult in space where the separation between the stations is not fixed, and where they are all moving independently with respect to the subject. But I thought it worth asking the question. The longer baselines available from space, and the lack of obstacles would seem to be advantages.

Is anyone aware of research on this idea?
With our current technology, interferometry in the optical part of the spectrum requires an optical pathway between the apertures. This requires that those apertures be no more than a few hundred meters apart. Much longer distances are possible at radio wavelengths, where the data can be stored locally and processed later. Space based radio telescopes operating this way are feasible. Optical ones, probably not.
Chris

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neufer
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Re: James Webb

Post by neufer » Tue Jun 22, 2021 3:07 pm

Chris Peterson wrote:
Tue Jun 22, 2021 1:33 pm
TerribleTadpole wrote:
Tue Jun 22, 2021 6:06 am

A friend of mine wondered whether we might be able to link observations from multiple orbital observatories using long-baseline-interferometry like we do on the ground. I suspect that it is much more difficult in space where the separation between the stations is not fixed, and where they are all moving independently with respect to the subject. But I thought it worth asking the question. The longer baselines available from space, and the lack of obstacles would seem to be advantages.

Is anyone aware of research on this idea?
With our current technology, interferometry in the optical part of the spectrum requires an optical pathway between the apertures. This requires that those apertures be no more than a few hundred meters apart. Much longer distances are possible at radio wavelengths, where the data can be stored locally and processed later. Space based radio telescopes operating this way are feasible. Optical ones, probably not.
https://en.wikipedia.org/wiki/Space_Interferometry_Mission wrote:
<<The Space Interferometry Mission, or SIM Lite, was a planned space telescope proposed by the NASA, in conjunction with contractor Northrop Grumman. One of the main goals of the mission was the hunt for Earth-sized planets orbiting in the habitable zones of nearby stars other than the Sun.

The SIM Lite telescope functions through optical interferometry. SIM was to be composed of one science interferometer (50 cm collectors, 6 m separation [baseline]), a guide interferometer (30 cm collectors, 4.2 m baseline), and a guide telescope (30 cm aperture). The sophisticated guide telescope stabilizes instrument pointing in the third dimension. The spacecraft's operational limiting magnitude would have gone down to 20 at 20 millionths of an arcsecond (μas) and its planet-finding, astrometric accuracy of 1.12 μas is for single measurements. The accuracy of its global, all-sky astrometric grid would have been 4 μas.

SIM's design since 2000 consisted of two light collectors (strictly speaking, they are Mersenne telescopes) mounted on opposite ends of a six-meter structure. The observatory would have been able to measure the small wobbles in stars and detect the planets causing them down to one Earth mass at distances up to 33 light years (10 parsecs) from the Sun.>>
https://en.wikipedia.org/wiki/HALCA wrote:
<<HALCA (Highly Advanced Laboratory for Communications and Astronomy), also known for its project name VSOP (VLBI Space Observatory Programme), was a Japanese 8 meter diameter radio telescope satellite which was used for Very Long Baseline Interferometry (VLBI). It was the first such space-borne dedicated VLBI mission.

It was placed in a highly elliptical orbit with an apogee altitude of 21,400 km and a perigee altitude of 560 km, with an orbital period of approximately 6.3 hours. This orbit allowed imaging of celestial radio sources by the satellite in conjunction with an array of ground-based radio telescopes, such that both good (u,v) plane coverage and very high resolution were obtained.

HALCA was launched in February 1997 from Kagoshima Space Center, and made its final VSOP observations in October 2003, far exceeding its 3-year predicted lifespan, before the loss of attitude control. All operations were officially ended in November 2005.

A follow-up mission ASTRO-G (VSOP-2) was planned, with a proposed launch date of 2012, but the project was eventually cancelled in 2011 due to increasing costs and the difficulties of achieving its science goals. It was expected to achieve resolutions up to ten times higher and up to ten times greater sensitivity than its predecessor HALCA. The cancellation of ASTRO-G left the Russian Spektr-R mission as the only then operational space VLBI facility.>>
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Re: James Webb

Post by Orca » Thu Jun 24, 2021 8:16 pm

BaldEagle wrote:
Thu Dec 12, 2019 1:35 am
Aside from looking deeper into space, what new revelations should we expect to see with the James Webb?

Will the Webb take us further toward the big bang and fine-tuning of the age of the Universe? If so, how far into the beginning of spacetime?

What will the various filtering show us? Will we be able to see into the center of galaxies?

Will the Webb allow us to see deeper into our own Milky Way galaxy?

How much improved detail can we expect viewing galaxies? Individual stars? And/or planets?

Thank you.
Here's a good comparison of HST and JWST:

https://www.jwst.nasa.gov/content/about ... ubble.html

Aside from the increased size of its primary mirror, perhaps the most important difference between the two instruments is that JWST will be working in the infrared range of the EM spectrum. This will allow JWST to cut through interstellar gas and dust. The new telescope will be able to see more clearly into our own galaxy, for example, which is heavily obscured in the optical range.

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Re: James Webb

Post by Daniel DeSclafani » Wed Oct 06, 2021 6:10 pm

Orca wrote:
Thu Jun 24, 2021 8:16 pm
BaldEagle wrote:
Thu Dec 12, 2019 1:35 am
Aside from looking deeper into space, what new revelations should we expect to see with the James Webb?

Will the Webb take us further toward the big bang and fine-tuning of the age of the Universe? If so, how far into the beginning of spacetime?

What will the various filtering show us? Will we be able to see into the center of galaxies?

Will the Webb allow us to see deeper into our own Milky Way galaxy?

How much improved detail can we expect viewing galaxies? Individual stars? And/or planets?

Thank you.
Here's a good comparison of HST and JWST:

https://www.jwst.nasa.gov/content/about ... ubble.html

Aside from the increased size of its primary mirror, perhaps the most important difference between the two instruments is that JWST will be working in the infrared range of the EM spectrum. This will allow JWST to cut through interstellar gas and dust. The new telescope will be able to see more clearly into our own galaxy, for example, which is heavily obscured in the optical range.
That is going to be exciting. May I ask though why that is not possible already? it seems we have some of the same technology here, thought this would have been done? What new things will they look through our galaxy for? Genuinely asking as well, not challenging your response! Thanks :ssmile:

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Chris Peterson
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Re: James Webb

Post by Chris Peterson » Wed Oct 06, 2021 6:15 pm

Daniel DeSclafani wrote:
Wed Oct 06, 2021 6:10 pm
Orca wrote:
Thu Jun 24, 2021 8:16 pm
BaldEagle wrote:
Thu Dec 12, 2019 1:35 am
Aside from looking deeper into space, what new revelations should we expect to see with the James Webb?

Will the Webb take us further toward the big bang and fine-tuning of the age of the Universe? If so, how far into the beginning of spacetime?

What will the various filtering show us? Will we be able to see into the center of galaxies?

Will the Webb allow us to see deeper into our own Milky Way galaxy?

How much improved detail can we expect viewing galaxies? Individual stars? And/or planets?

Thank you.
Here's a good comparison of HST and JWST:

https://www.jwst.nasa.gov/content/about ... ubble.html

Aside from the increased size of its primary mirror, perhaps the most important difference between the two instruments is that JWST will be working in the infrared range of the EM spectrum. This will allow JWST to cut through interstellar gas and dust. The new telescope will be able to see more clearly into our own galaxy, for example, which is heavily obscured in the optical range.
That is going to be exciting. May I ask though why that is not possible already? it seems we have some of the same technology here, thought this would have been done? What new things will they look through our galaxy for? Genuinely asking as well, not challenging your response! Thanks :ssmile:
It's been possible for a long time. It just requires money and effort to get it into space. Many of the interesting wavelengths here are blocked by our atmosphere.
Chris

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Daniel DeSclafani
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Re: James Webb

Post by Daniel DeSclafani » Wed Oct 06, 2021 6:28 pm

Chris Peterson wrote:
Wed Oct 06, 2021 6:15 pm
Daniel DeSclafani wrote:
Wed Oct 06, 2021 6:10 pm
Orca wrote:
Thu Jun 24, 2021 8:16 pm


Here's a good comparison of HST and JWST:

https://www.jwst.nasa.gov/content/about ... ubble.html

Aside from the increased size of its primary mirror, perhaps the most important difference between the two instruments is that JWST will be working in the infrared range of the EM spectrum. This will allow JWST to cut through interstellar gas and dust. The new telescope will be able to see more clearly into our own galaxy, for example, which is heavily obscured in the optical range.
That is going to be exciting. May I ask though why that is not possible already? it seems we have some of the same technology here, thought this would have been done? What new things will they look through our galaxy for? Genuinely asking as well, not challenging your response! Thanks :ssmile:
It's been possible for a long time. It just requires money and effort to get it into space. Many of the interesting wavelengths here are blocked by our atmosphere.
Awesome, and absolutely makes sense. atmosphere blocking different wavelengths. The infrared wavelength is the strongest when we look all the way back correct? Which is part of the reason we are using JWST right? Just trying to remember everything I learned, I believe infrared is most of what's left from older galaxies and such right?

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Re: James Webb

Post by Lariliss » Tue Oct 12, 2021 12:25 pm

With James Webb Telescope astronomers hope to:
1. Study new galaxies that are close to the edge of the observable universe.
2. Find the first aggregations of stars that formed after the Big Bang.
3. Observe exoplanets with transmission spectroscopy.
4. Observe ‘earth-like atmospheres around other planets.
5. Study of the Universe expansion.