<p>Yes.</p>
<p>Wave interference is the only phenomenon in science that gets easier to see, the smaller it is. Interferometry works, but like putting an eyepiece in your telescope that's too strong, you can zoom in as much as you want, but the image rapidly grows too dim to see. So you can only use optical interferometry for very bright things.</p>
<p>Like Betelgeuse:</p>
<p><a href="https://i.sstatic.net/TSZpURJj.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/TSZpURJj.jpg" alt="Betelgeuse" /></a></p>
<p>And Regulus:</p>
<p><a href="https://i.sstatic.net/2dBdqBM6.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/2dBdqBM6.jpg" alt="Regulus" /></a></p>
<p>And Altair:</p>
<p><a href="https://i.sstatic.net/9QHIlZ6K.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/9QHIlZ6K.jpg" alt="enter image description here" /></a></p>
<p>And orbiting binaries:</p>
<p><a href="https://i.sstatic.net/JYxHxO2C.gif" rel="nofollow noreferrer"><img src="https://i.sstatic.net/JYxHxO2C.gif" alt="enter image description here" /></a></p>

CC BY-SA 4.0
2024-06-06T11:46:21.673Z
2024-06-06T12:05:20.887Z
2024-06-06T12:05:20.887Z
Miss Understands
<p>Have any stars (other than Sol) been imaged as actual disks (the way we've seen the planets and moons of our solar system)? Presumably such a star would be relatively close to us and/or relatively large, and the imaging device would have to be capable of very high resolution. Which telescopes are or might be capable of such a feat, which (if any) stars have a large enough apparent size due to proximity and/or actual size that they could be imaged, and if so, what was/were the subject stars and telescope(s) used?</p>
<p>For this question I am considering stars which shine in the visible spectrum, so anything from red dwarfs to the various stars of Alpha Centauri red supergiants like Betelgeuse to blue giants like Bellatrix, etc.</p>

CC BY-SA 4.0
2024-06-04T20:14:43.453Z
Do supermassive black holes count as stars for the purposes of your question?
Charles Staats
CC BY-SA 4.0
2024-06-04T20:32:43.183Z
Wikipedia has a list: https://en.wikipedia.org/wiki/List_of_stars_with_resolved_images with links to more information about the resolving telescopes.
Russell Borogove
CC BY-SA 4.0
2024-06-04T23:24:22.673Z
@RussellBorogove - that's an interesting list, especially the included photos of some "disks". I would think that beyond just the ability to resolve a star as more than one pixel, the ability to actually resolve the shape as a disk depends on not only the angular capability of the lens, but also the resolution of the detector. And probably also the capability of the software used for post processing of the images.
Steve Pemberton
CC BY-SA 4.0
2024-06-06T09:17:08.547Z
@CharlesStaats do supermassive black holes have "actual disks"? That's not the same as accretion disks.
uhoh
CC BY-SA 4.0
2024-06-06T13:07:48.680Z
@StevePemberton The optical limit of diffraction is here the hard criterion; pixel size of the detectors does not play a role here as one usually chooses them such that they match the diffraction limit.
planetmaker
CC BY-SA 4.0
2024-06-06T14:42:30.553Z
@uhoh I guess it depends on your definitions. A black hole has a disk, in the sense that the event horizon (and the shadow, which is roughly 2x larger) subtends a region of the sky. You can "image" this disk if you can resolve that region into more than one pixel, with sufficient sensitivity to see any light coming from that region (if there were any). I *believe* that the Event Horizon Telescope pictures satisfy both of these requirements in demonstrating that light from a certain region of the sky is being blocked, so in this sense, we have imaged the disks of supermassive black holes.
Charles Staats
CC BY-SA 4.0
2024-06-06T15:57:26.340Z
@CharlesStaats well they do specify "star" and "disk" and "stars which shine in the visible spectrum". I don't see how either an event horizon (which isn't really a thing) or an accretion disk (whose spectrum does include visible as well as radio, but is a donut rather than a disk) matches the description in the question. I don't think "that which subtends a region of the sky" is sufficient in this case.
uhoh
CC BY-SA 4.0
2024-06-06T17:49:05.377Z
@CharlesStaats I was thinking only of "star-like" objects, not black holes which do not themselves emit light, and whose accretion disks (where light is emitted) can be quite large.
Anthony X
<photography>
Stars (other than Sol) resolvable as disks
Anthony X
# Stars (other than Sol) resolvable as disks

(Asked by: username_0 on 2024-06-04)

Have any stars (other than Sol) been imaged as actual disks (the way we've seen the planets and moons of our solar system)? Presumably such a star would be relatively close to us and/or relatively large, and the imaging device would have to be capable of very high resolution. Which telescopes are or might be capable of such a feat, which (if any) stars have a large enough apparent size due to proximity and/or actual size that they could be imaged, and if so, what was/were the subject stars and telescope(s) used?

For this question I am considering stars which shine in the visible spectrum, so anything from red dwarfs to the various stars of Alpha Centauri red supergiants like Betelgeuse to blue giants like Bellatrix, etc.

**Tags:** photography

> **Comments:**
> **username_1**: Do supermassive black holes count as stars for the purposes of your question?  
> **username_2**: Wikipedia has a list: https://en.wikipedia.org/wiki/List_of_stars_with_resolved_images with links to more information about the resolving telescopes.  
> **username_3**: @username_2 - that's an interesting list, especially the included photos of some "disks". I would think that beyond just the ability to resolve a star as more than one pixel, the ability to actually resolve the shape as a disk depends on not only the angular capability of the lens, but also the resolution of the detector. And probably also the capability of the software used for post processing of the images.  
> **username_4**: @username_1 do supermassive black holes have "actual disks"? That's not the same as accretion disks.  
> **username_5**: @username_3 The optical limit of diffraction is here the hard criterion; pixel size of the detectors does not play a role here as one usually chooses them such that they match the diffraction limit.  
> **username_1**: @username_4 I guess it depends on your definitions. A black hole has a disk, in the sense that the event horizon (and the shadow, which is roughly 2x larger) subtends a region of the sky. You can "image" this disk if you can resolve that region into more than one pixel, with sufficient sensitivity to see any light coming from that region (if there were any). I *believe* that the Event Horizon Telescope pictures satisfy both of these requirements in demonstrating that light from a certain region of the sky is being blocked, so in this sense, we have imaged the disks of supermassive black holes.  
> **username_4**: @username_1 well they do specify "star" and "disk" and "stars which shine in the visible spectrum". I don't see how either an event horizon (which isn't really a thing) or an accretion disk (whose spectrum does include visible as well as radio, but is a donut rather than a disk) matches the description in the question. I don't think "that which subtends a region of the sky" is sufficient in this case.  
> **username_0**: @username_1 I was thinking only of "star-like" objects, not black holes which do not themselves emit light, and whose accretion disks (where light is emitted) can be quite large.  

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## 1 answers

### Answer by username_6 on 2024-06-06. Score: 4

Yes.

Wave interference is the only phenomenon in science that gets easier to see, the smaller it is. Interferometry works, but like putting an eyepiece in your telescope that's too strong, you can zoom in as much as you want, but the image rapidly grows too dim to see. So you can only use optical interferometry for very bright things.

Like Betelgeuse:

[![Betelgeuse](https://i.sstatic.net/TSZpURJj.jpg)](https://i.sstatic.net/TSZpURJj.jpg)

And Regulus:

[![Regulus](https://i.sstatic.net/2dBdqBM6.jpg)](https://i.sstatic.net/2dBdqBM6.jpg)

And Altair:

[![enter image description here](https://i.sstatic.net/9QHIlZ6K.jpg)](https://i.sstatic.net/9QHIlZ6K.jpg)

And orbiting binaries:

[![enter image description here](https://i.sstatic.net/JYxHxO2C.gif)](https://i.sstatic.net/JYxHxO2C.gif)


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