My son is in college and writing a paper on this unusual star after
first becoming interested in it from the rather vague Hubble images.
With it's more recent variability episodes, he's wondering what the star
would actually look like up close (close meaning the equivalent of how
our sun appears to us)? It almost certainly wouldn't be spherical I
wouldn't think. Are there any illustrations that could be shared as to
it's approximate appearance>

thanks,
Jay T

On 01/09/2023 13:18, Jay Taat wrote:
> My son is in college and writing a paper on this unusual star after
> first becoming interested in it from the rather vague Hubble images.
> With it's more recent variability episodes, he's wondering what the star
> would actually look like up close (close meaning the equivalent of how
> our sun appears to us)?  It almost certainly wouldn't be spherical I
> wouldn't think.  Are there any illustrations that could be shared as to
> it's approximate appearance>

Not really. There are plenty of artist's impressions though.
Some are a more fanciful than others.

The highest resolution image to date is in the mm waveband from ALMA

https://www.space.com/37344-alma-captures-clearest-image-of-betelgeuse.html

It strikes me that with Doppler methods and the occasional bright
feature on the surface there may be a guestimate of its rotation speed
which together with its radius will determine how oblate it actually is.

Our sun is a pretty good approximation to a sphere (rotates ~24-30 days)
whereas Jupiter clearly is oval shaped (rotates every 8 hours or so).

Wiki has quite a decent article on its apparent diameter as a function
of observing wavelength.

https://en.wikipedia.org/wiki/Betelgeuse#Diameter

Several other big radius stars have been targets for indirect imaging or
determinations of their diameters by optical interferometry. It has a
long history going back to Michelson & Pease in the 1920's.

https://www.mtwilson.edu/news/discovering-mount-wilson-chapter-11-the-stellar-interferometer/

--
Martin Brown

On 9/1/23 10:13 AM, Martin Brown wrote:
> On 01/09/2023 13:18, Jay Taat wrote:
>> My son is in college and writing a paper on this unusual star after
>> first becoming interested in it from the rather vague Hubble images.
>> With it's more recent variability episodes, he's wondering what the
>> star would actually look like up close (close meaning the equivalent
>> of how our sun appears to us)?  It almost certainly wouldn't be
>> spherical I wouldn't think.  Are there any illustrations that could be
>> shared as to it's approximate appearance>
>
> Not really. There are plenty of artist's impressions though.
> Some are a more fanciful than others.
>
> The highest resolution image to date is in the mm waveband from ALMA
>
> https://www.space.com/37344-alma-captures-clearest-image-of-betelgeuse.html
>
> It strikes me that with Doppler methods and the occasional bright
> feature on the surface there may be a guestimate of its rotation speed
> which together with its radius will determine how oblate it actually is.
>
> Our sun is a pretty good approximation to a sphere (rotates ~24-30 days)
> whereas Jupiter clearly is oval shaped (rotates every 8 hours or so).
>
> Wiki has quite a decent article on its apparent diameter as a function
> of observing wavelength.
>
> https://en.wikipedia.org/wiki/Betelgeuse#Diameter
>
> Several other big radius stars have been targets for indirect imaging or
> determinations of their diameters by optical interferometry. It has a
> long history going back to Michelson & Pease in the 1920's.
>
> https://www.mtwilson.edu/news/discovering-mount-wilson-chapter-11-the-stellar-interferometer/
>
Thanks. Unfortunately, that's not a lot to go on and was hoping for a
bit better resolution, but will take what I can get.
I remember Pluto looking similar until of course the probe visited there
and completely changed our existing images and conceptions of that
remote world. Too bad Betelgeuse is too far away for similar results.
JT