So how would JWT see our closest star, or resolve it?
Would it see any meaning full details?

On Tue, 12 Jul 2022 22:51:51 -0700 (PDT), StarDust <csoka01@gmail.com>
wrote:

>So how would JWT see our closest star, or resolve it?
>Would it see any meaning full details?

The HST is better for that. Same resolution, and sensitive in a
wavelength band appropriate for the target.

On 13/07/2022 06:51, StarDust wrote:
> So how would JWT see our closest star, or resolve it?
> Would it see any meaning full details?

Sadly not. I suspect it would also be too bright for the sensors to
handle without special measures for very short exposures.

HST can get Betelgeuse just about resolved as a disk with some detail so
in principle the JWT should be able to do about the same (but it has
more stringent maximum allowed surface brightness for its targets).

Best bet for indirect images of stars is ground based (for now) optical
interferometry exemplified by the prototype COAST array in Cambridge and
now fully operational systems like CHARA - has seen spots on other stars!

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

They are using radio astronomy VLBI techniques in the near IR band.

--
Regards,
Martin Brown

On Mon, 18 Jul 2022 15:59:18 +0100, Martin Brown
<'''newspam'''@nonad.co.uk> wrote:

>On 13/07/2022 06:51, StarDust wrote:
>> So how would JWT see our closest star, or resolve it?
>> Would it see any meaning full details?
>
>Sadly not. I suspect it would also be too bright for the sensors to
>handle without special measures for very short exposures.
>
>HST can get Betelgeuse just about resolved as a disk with some detail so
>in principle the JWT should be able to do about the same (but it has
>more stringent maximum allowed surface brightness for its targets).
>
>Best bet for indirect images of stars is ground based (for now) optical
>interferometry exemplified by the prototype COAST array in Cambridge and
>now fully operational systems like CHARA - has seen spots on other stars!
>
>https://en.wikipedia.org/wiki/CHARA_array
>
>They are using radio astronomy VLBI techniques in the near IR band.

And all of the large ground-based telescopes offer higher resolution
of stars than any space telescope. Without interferometry.

On Monday, July 18, 2022 at 11:31:23 AM UTC-6, Chris L Peterson wrote:

> And all of the large ground-based telescopes offer higher resolution
> of stars than any space telescope. Without interferometry.

But with adaptive optics and stuff like that. The Earth's atmosphere,
while very useful for purposes like breathing, is a pain for astronomy.

John Savard

On Thursday, July 21, 2022 at 5:17:46 PM UTC-6, Quadibloc wrote:
> On Monday, July 18, 2022 at 11:31:23 AM UTC-6, Chris L Peterson wrote:

> > And all of the large ground-based telescopes offer higher resolution
> > of stars than any space telescope. Without interferometry.

> But with adaptive optics and stuff like that. The Earth's atmosphere,
> while very useful for purposes like breathing, is a pain for astronomy.

....but more to the point, even in telescopes like the Keck, stars are
still just point objects, even if their angular resolution beats the Hubble
and the JWST.

Long-baseline methods with interferometry are needed to see sunspots
on distant stars at present.

John Savard

On Thu, 21 Jul 2022 16:17:45 -0700 (PDT), Quadibloc
<jsavard@ecn.ab.ca> wrote:

>On Monday, July 18, 2022 at 11:31:23 AM UTC-6, Chris L Peterson wrote:
>
>> And all of the large ground-based telescopes offer higher resolution
>> of stars than any space telescope. Without interferometry.
>
>But with adaptive optics and stuff like that. The Earth's atmosphere,
>while very useful for purposes like breathing, is a pain for astronomy.

Yes. But the size of the large mirrors combined with adaptive optics
makes ground-based telescopes the highest resolution instruments we
have for looking at small-angle objects like stars.

On Thu, 21 Jul 2022 16:20:14 -0700 (PDT), Quadibloc
<jsavard@ecn.ab.ca> wrote:

>On Thursday, July 21, 2022 at 5:17:46 PM UTC-6, Quadibloc wrote:
>> On Monday, July 18, 2022 at 11:31:23 AM UTC-6, Chris L Peterson wrote:
>
>> > And all of the large ground-based telescopes offer higher resolution
>> > of stars than any space telescope. Without interferometry.
>
>> But with adaptive optics and stuff like that. The Earth's atmosphere,
>> while very useful for purposes like breathing, is a pain for astronomy.
>
>...but more to the point, even in telescopes like the Keck, stars are
>still just point objects, even if their angular resolution beats the Hubble
>and the JWST.
>
>Long-baseline methods with interferometry are needed to see sunspots
>on distant stars at present.

Keck has sufficient resolution to resolve several stars.