https://www.bbc.com/news/science-environment-60931100

They've nicknamed it "Earendel" and it's the most distant, single star yet imaged by a telescope.

The light from this object has taken 12.9 billion years to reach us.

It's at the sort of distance that telescopes normally would only be able to resolve galaxies containing millions of stars.

But the Hubble space observatory has picked out Earendel individually by exploiting a natural phenomenon that's akin to using a zoom lens.

It's called gravitational lensing and it works like this:

I wonder, how JWT will resolve this distant star, when ready?

On 31/03/2022 09:57, StarDust wrote:
> https://www.bbc.com/news/science-environment-60931100
>
> They've nicknamed it "Earendel" and it's the most distant, single star yet imaged by a telescope.
>
> The light from this object has taken 12.9 billion years to reach us.
>
> It's at the sort of distance that telescopes normally would only be able to resolve galaxies containing millions of stars.
>
> But the Hubble space observatory has picked out Earendel individually by exploiting a natural phenomenon that's akin to using a zoom lens.
>
> It's called gravitational lensing and it works like this:
>
> I wonder, how JWT will resolve this distant star, when ready?

They will likely target it PDQ if it is in the zone where JWT can look
at it. The stars proper motion will take it out of the sweet spot for
imaging in an as yet undetermined period of time.

The JWT IR spectrograph would be ideally suited to the job.

--
Regards,
Martin Brown

On Thu, 31 Mar 2022 01:57:11 -0700 (PDT), StarDust <csoka01@gmail.com>
wrote:

>https://www.bbc.com/news/science-environment-60931100
>
>They've nicknamed it "Earendel" and it's the most distant, single star yet imaged by a telescope.
>
>The light from this object has taken 12.9 billion years to reach us.
>
>It's at the sort of distance that telescopes normally would only be able to resolve galaxies containing millions of stars.
>
>But the Hubble space observatory has picked out Earendel individually by exploiting a natural phenomenon that's akin to using a zoom lens.
>
>It's called gravitational lensing and it works like this:
>
>I wonder, how JWT will resolve this distant star, when ready?

To be clear, the star isn't resolved, just detected. Presumably
because it is so massive that it's very hot, and therefore has most of
its output in the UV, meaning that even with its massive redshift
there's enough energy left in the visible spectrum for HST to detect
it.

There are two big differences between HST and JWST. The latter is much
more sensitive, and the latter works in the IR spectrum. Therefore, it
will be capable of directly detecting stars like this one without
requiring the lucky chance of a gravitational lens to boost the
signal. It should also be able to detect cooler stars.

On 31/03/2022 14:42, Chris L Peterson wrote:
> On Thu, 31 Mar 2022 01:57:11 -0700 (PDT), StarDust <csoka01@gmail.com>
> wrote:
>
>> https://www.bbc.com/news/science-environment-60931100
>>
>> They've nicknamed it "Earendel" and it's the most distant, single star yet imaged by a telescope.
>>
>> The light from this object has taken 12.9 billion years to reach us.
>>
>> It's at the sort of distance that telescopes normally would only be able to resolve galaxies containing millions of stars.
>>
>> But the Hubble space observatory has picked out Earendel individually by exploiting a natural phenomenon that's akin to using a zoom lens.
>>
>> It's called gravitational lensing and it works like this:
>>
>> I wonder, how JWT will resolve this distant star, when ready?
>
> To be clear, the star isn't resolved, just detected. Presumably
> because it is so massive that it's very hot, and therefore has most of
> its output in the UV, meaning that even with its massive redshift
> there's enough energy left in the visible spectrum for HST to detect
> it.
>
> There are two big differences between HST and JWST. The latter is much
> more sensitive, and the latter works in the IR spectrum. Therefore, it
> will be capable of directly detecting stars like this one without
> requiring the lucky chance of a gravitational lens to boost the
> signal. It should also be able to detect cooler stars.

I doubt if it will be able to see anything by way of individual stars
that far away without the aid of a galaxy cluster lensing them.

It will see galaxies out to some considerably greater distance though.

There is a golden opportunity of JWST to do a high resolution spectrum
of this star which could be very interesting indeed to show how much by
way of metals it has and if it is indeed a true first generation star.

I presume the claimed distance is inferred from its redshift measurement
so they must have some sort of spectrum already.

--
Regards,
Martin Brown

On Thu, 31 Mar 2022 15:46:08 +0100, Martin Brown
<'''newspam'''@nonad.co.uk> wrote:

>On 31/03/2022 14:42, Chris L Peterson wrote:
>> On Thu, 31 Mar 2022 01:57:11 -0700 (PDT), StarDust <csoka01@gmail.com>
>> wrote:
>>
>>> https://www.bbc.com/news/science-environment-60931100
>>>
>>> They've nicknamed it "Earendel" and it's the most distant, single star yet imaged by a telescope.
>>>
>>> The light from this object has taken 12.9 billion years to reach us.
>>>
>>> It's at the sort of distance that telescopes normally would only be able to resolve galaxies containing millions of stars.
>>>
>>> But the Hubble space observatory has picked out Earendel individually by exploiting a natural phenomenon that's akin to using a zoom lens.
>>>
>>> It's called gravitational lensing and it works like this:
>>>
>>> I wonder, how JWT will resolve this distant star, when ready?
>>
>> To be clear, the star isn't resolved, just detected. Presumably
>> because it is so massive that it's very hot, and therefore has most of
>> its output in the UV, meaning that even with its massive redshift
>> there's enough energy left in the visible spectrum for HST to detect
>> it.
>>
>> There are two big differences between HST and JWST. The latter is much
>> more sensitive, and the latter works in the IR spectrum. Therefore, it
>> will be capable of directly detecting stars like this one without
>> requiring the lucky chance of a gravitational lens to boost the
>> signal. It should also be able to detect cooler stars.
>
>I doubt if it will be able to see anything by way of individual stars
>that far away without the aid of a galaxy cluster lensing them.
>
>It will see galaxies out to some considerably greater distance though.
>
>There is a golden opportunity of JWST to do a high resolution spectrum
>of this star which could be very interesting indeed to show how much by
>way of metals it has and if it is indeed a true first generation star.
>
>I presume the claimed distance is inferred from its redshift measurement
>so they must have some sort of spectrum already.

I believe it could detect this particular star without any
gravitational lensing.

Such a specious and contrived set-up, but it certainly got headlines over 100 years ago-

https://en.wikipedia.org/wiki/Eddington_experiment

Not to throw good information after bad, observers today have permanent solar eclipse conditions by which to judge the Earth's orbital motion using the change in position of the stars from left to right of the central star at the centre of all planetary motions-

https://sol24.net/data/html/SOHO/C3/96H/VIDEO/

Using a celestial sphere or RA/Dec framework is a timekeeping facility which is a property of the 365/366 day calendar framework to a close proximity so any values the 1919 folk tried to extract by gauging a background star close to our Sun is wishful thinking and certainly non-astronomical.

In any case, throwing good information after bad is not the purpose here, it is that people are already aware of the observations the background stars play in terms of the foreground Sun as a demonstration of the Earth's own orbital motion.

On 31/03/2022 17:02, Chris L Peterson wrote:
> On Thu, 31 Mar 2022 15:46:08 +0100, Martin Brown
> <'''newspam'''@nonad.co.uk> wrote:
>
>> On 31/03/2022 14:42, Chris L Peterson wrote:
>>> On Thu, 31 Mar 2022 01:57:11 -0700 (PDT), StarDust <csoka01@gmail.com>
>>> wrote:
>>>
>>>> https://www.bbc.com/news/science-environment-60931100
>>>>
>>>> They've nicknamed it "Earendel" and it's the most distant, single star yet imaged by a telescope.
>>>>
>>>> The light from this object has taken 12.9 billion years to reach us.
>>>>
>>>> It's at the sort of distance that telescopes normally would only be able to resolve galaxies containing millions of stars.
>>>>
>>>> But the Hubble space observatory has picked out Earendel individually by exploiting a natural phenomenon that's akin to using a zoom lens.
>>>>
>>>> It's called gravitational lensing and it works like this:
>>>>
>>>> I wonder, how JWT will resolve this distant star, when ready?
>>>
>>> To be clear, the star isn't resolved, just detected. Presumably
>>> because it is so massive that it's very hot, and therefore has most of
>>> its output in the UV, meaning that even with its massive redshift
>>> there's enough energy left in the visible spectrum for HST to detect
>>> it.
>>>
>>> There are two big differences between HST and JWST. The latter is much
>>> more sensitive, and the latter works in the IR spectrum. Therefore, it
>>> will be capable of directly detecting stars like this one without
>>> requiring the lucky chance of a gravitational lens to boost the
>>> signal. It should also be able to detect cooler stars.
>>
>> I doubt if it will be able to see anything by way of individual stars
>> that far away without the aid of a galaxy cluster lensing them.
>>
>> It will see galaxies out to some considerably greater distance though.
>>
>> There is a golden opportunity of JWST to do a high resolution spectrum
>> of this star which could be very interesting indeed to show how much by
>> way of metals it has and if it is indeed a true first generation star.
>>
>> I presume the claimed distance is inferred from its redshift measurement
>> so they must have some sort of spectrum already.
>
> I believe it could detect this particular star without any
> gravitational lensing.

That doesn't seem likely to me. I would believe JWST could easily see a
Type I supernova at that distance or possibly even a little more but a
solitary fast burning supermassive star will be beyond its light grasp.
(until it goes supernova)

The fields imaged so far look well populated with galaxies and not so
many lone stars (but they are avoiding any local galaxy bright stars).

--
Regards,
Martin Brown

On Fri, 1 Apr 2022 15:39:03 +0100, Martin Brown
<'''newspam'''@nonad.co.uk> wrote:

>On 31/03/2022 17:02, Chris L Peterson wrote:
>> On Thu, 31 Mar 2022 15:46:08 +0100, Martin Brown
>> <'''newspam'''@nonad.co.uk> wrote:
>>
>>> On 31/03/2022 14:42, Chris L Peterson wrote:
>>>> On Thu, 31 Mar 2022 01:57:11 -0700 (PDT), StarDust <csoka01@gmail.com>
>>>> wrote:
>>>>
>>>>> https://www.bbc.com/news/science-environment-60931100
>>>>>
>>>>> They've nicknamed it "Earendel" and it's the most distant, single star yet imaged by a telescope.
>>>>>
>>>>> The light from this object has taken 12.9 billion years to reach us.
>>>>>
>>>>> It's at the sort of distance that telescopes normally would only be able to resolve galaxies containing millions of stars.
>>>>>
>>>>> But the Hubble space observatory has picked out Earendel individually by exploiting a natural phenomenon that's akin to using a zoom lens.
>>>>>
>>>>> It's called gravitational lensing and it works like this:
>>>>>
>>>>> I wonder, how JWT will resolve this distant star, when ready?
>>>>
>>>> To be clear, the star isn't resolved, just detected. Presumably
>>>> because it is so massive that it's very hot, and therefore has most of
>>>> its output in the UV, meaning that even with its massive redshift
>>>> there's enough energy left in the visible spectrum for HST to detect
>>>> it.
>>>>
>>>> There are two big differences between HST and JWST. The latter is much
>>>> more sensitive, and the latter works in the IR spectrum. Therefore, it
>>>> will be capable of directly detecting stars like this one without
>>>> requiring the lucky chance of a gravitational lens to boost the
>>>> signal. It should also be able to detect cooler stars.
>>>
>>> I doubt if it will be able to see anything by way of individual stars
>>> that far away without the aid of a galaxy cluster lensing them.
>>>
>>> It will see galaxies out to some considerably greater distance though.
>>>
>>> There is a golden opportunity of JWST to do a high resolution spectrum
>>> of this star which could be very interesting indeed to show how much by
>>> way of metals it has and if it is indeed a true first generation star.
>>>
>>> I presume the claimed distance is inferred from its redshift measurement
>>> so they must have some sort of spectrum already.
>>
>> I believe it could detect this particular star without any
>> gravitational lensing.
>
>That doesn't seem likely to me. I would believe JWST could easily see a
>Type I supernova at that distance or possibly even a little more but a
>solitary fast burning supermassive star will be beyond its light grasp.
>(until it goes supernova)
>
>The fields imaged so far look well populated with galaxies and not so
>many lone stars (but they are avoiding any local galaxy bright stars).

One of the stated mission goals is the detection of isolated
Population III stars (assuming they exist). Lacking much detail about
the nature of such stars, the ability to detect them is uncertain, but
far from unlikely.