<p>Yes. See today's <a href="https://eventhorizontelescope.org/blog/astronomers-reveal-first-image-black-hole-heart-our-galaxy" rel="noreferrer">press release</a> from the Event Horizon Telescope. The image is remarkably similar to M87, but note that this a time-averaged composite over about 10 hours, because the emission from the smaller Milky Way black hole varies on timescales of minutes.</p>
<p>Sgr A* is about 1500 times less massive than the black hole in M87, but is two thousand times closer. Since the Schwarzschild radius scales linearly with mass then they turn out to have about the same angular size.</p>
<p>To make the comparison mor explicit, here are M87 and the Milky Way black hole side by side at the same angular scale (from the <a href="https://www.eso.org/public/news/eso2208-eht-mw/" rel="noreferrer">ESO press release</a>). The reliable feature of the Sgr A* image is the presence of a ring. Less reliable are the azimuthal &quot;lumps&quot;, which come and go in time and are not reliably reproduced in the various image reconstruction methods.</p>
<p><a href="https://i.sstatic.net/MHyUJ.jpg" rel="noreferrer"><img src="https://i.sstatic.net/MHyUJ.jpg" alt="M87 black hole compared with Sgr A*" /></a></p>

CC BY-SA 4.0
2022-05-12T15:35:03.757Z
2022-05-12T16:49:36.803Z
2022-05-12T16:49:36.803Z
ProfRob
<p><a href="https://astronomy.stackexchange.com/a/39341">@HDE226868's answer</a> to <em>Why doesn't the black hole in the center of the Milky Way glow similarly to the famous M87 image?</em> explains that neither black hole is orange and any <a href="https://en.wikipedia.org/wiki/Event_Horizon_Telescope" rel="nofollow noreferrer">Event Horizon Telescope</a> images will be made at about 1 mm (~300 GHz). It goes on to point out that there's going to be far less emission from Sgr A*'s accretion disk than there is from that one. Of course ours is a lot closer, but it's not always active; unless a dust cloud wanders by and falls in. For more on that see answers to <a href="https://astronomy.stackexchange.com/q/30339">Why not take a picture of a closer black hole?</a></p>
<p><a href="https://astronomy.stackexchange.com/a/30318">@RobJeffries' answer</a> to <em>How can the Event Horizon Telescope image Sgr A</em> when it's not visible from all sites at one time?* points out that our disk might also vary in appearance over timescales of minutes rather than months, so it's going to be a new challenge in terms of data processing.</p>
<p><strong>Question:</strong> Will the first Event Horizon Telescope image of the Milky Way's black hole be just another orange donut?</p>
<p>When all is said and done though, will the first EHT image of Sgr A* look pretty much like M87; a lumpy orange donut? I know there is an issue of inclination, but it won't look like it's <em>edge-on</em> because of the way light bends around, so I think it's necessary to consult a simulation. Another issue is the accretion source itself; will there be a disk or just spiraling filaments? Assuming the same wavelength and baseline there is a possibility of higher resolution, and the shorter timescale compared to M87 might be offset by a much sorter distance and therefore brightness.</p>

CC BY-SA 4.0
2020-10-13T15:49:56.090Z
companion question: [How will they know when to start taking the picture of the black hole at the center of the Milky Way?](https://astronomy.stackexchange.com/q/39354/7982)
uhoh
CC BY-SA 4.0
2022-05-12T15:58:19.830Z
For those of us who helped build the Event Horizon Telescope, the images are a heck of a lot more than just "lumpy orange donuts."  They represent remarkable scientific achievements in astronomy, enabled by cross-disciplinary teams over decades.
Connor Garcia
CC BY-SA 4.0
2022-05-12T19:04:25.987Z
@ConnorGarcia indeed! The mass of the W boson [turns the standard model on its side](https://mattermodeling.stackexchange.com/a/9045/201) and yet it's *just a number* and an uncertainty (80433.5 ± 9.4 MeV) thought it certainly represents a  remarkable scientific achievements at the same time.
uhoh
<observational-astronomy><radio-astronomy><supermassive-black-hole><image-processing><event-horizon-telescope>
Will the first Event Horizon Telescope image of the Milky Way's black hole Sgr A* just be another lumpy orange donut?
uhoh
# Will the first Event Horizon Telescope image of the Milky Way's black hole Sgr A* just be another lumpy orange donut?

(Asked by: username_0 on 2020-10-13)

[@HDE226868's answer](https://astronomy.stackexchange.com/a/39341) to *Why doesn't the black hole in the center of the Milky Way glow similarly to the famous M87 image?* explains that neither black hole is orange and any [Event Horizon Telescope](https://en.wikipedia.org/wiki/Event_Horizon_Telescope) images will be made at about 1 mm (~300 GHz). It goes on to point out that there's going to be far less emission from Sgr A\*'s accretion disk than there is from that one. Of course ours is a lot closer, but it's not always active; unless a dust cloud wanders by and falls in. For more on that see answers to [Why not take a picture of a closer black hole?](https://astronomy.stackexchange.com/q/30339)

[@RobJeffries' answer](https://astronomy.stackexchange.com/a/30318) to *How can the Event Horizon Telescope image Sgr A* when it's not visible from all sites at one time?\* points out that our disk might also vary in appearance over timescales of minutes rather than months, so it's going to be a new challenge in terms of data processing.

**Question:** Will the first Event Horizon Telescope image of the Milky Way's black hole be just another orange donut?

When all is said and done though, will the first EHT image of Sgr A\* look pretty much like M87; a lumpy orange donut? I know there is an issue of inclination, but it won't look like it's *edge-on* because of the way light bends around, so I think it's necessary to consult a simulation. Another issue is the accretion source itself; will there be a disk or just spiraling filaments? Assuming the same wavelength and baseline there is a possibility of higher resolution, and the shorter timescale compared to M87 might be offset by a much sorter distance and therefore brightness.

**Tags:** observational-astronomy, radio-astronomy, supermassive-black-hole, image-processing, event-horizon-telescope

> **Comments:**
> **username_0**: companion question: [How will they know when to start taking the picture of the black hole at the center of the Milky Way?](https://astronomy.stackexchange.com/q/39354/7982)  
> **username_1**: For those of us who helped build the Event Horizon Telescope, the images are a heck of a lot more than just "lumpy orange donuts."  They represent remarkable scientific achievements in astronomy, enabled by cross-disciplinary teams over decades.  
> **username_0**: @username_1 indeed! The mass of the W boson [turns the standard model on its side](https://mattermodeling.stackexchange.com/a/9045/201) and yet it's *just a number* and an uncertainty (80433.5 ± 9.4 MeV) thought it certainly represents a  remarkable scientific achievements at the same time.  

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## 1 answers

### Answer by username_2 on 2022-05-12. Score: 7 | Accepted answer

Yes. See today's [press release](https://eventhorizontelescope.org/blog/astronomers-reveal-first-image-black-hole-heart-our-galaxy) from the Event Horizon Telescope. The image is remarkably similar to M87, but note that this a time-averaged composite over about 10 hours, because the emission from the smaller Milky Way black hole varies on timescales of minutes.

Sgr A\* is about 1500 times less massive than the black hole in M87, but is two thousand times closer. Since the Schwarzschild radius scales linearly with mass then they turn out to have about the same angular size.

To make the comparison mor explicit, here are M87 and the Milky Way black hole side by side at the same angular scale (from the [ESO press release](https://www.eso.org/public/news/eso2208-eht-mw/)). The reliable feature of the Sgr A\* image is the presence of a ring. Less reliable are the azimuthal "lumps", which come and go in time and are not reliably reproduced in the various image reconstruction methods.

[![M87 black hole compared with Sgr A*](https://i.sstatic.net/MHyUJ.jpg)](https://i.sstatic.net/MHyUJ.jpg)


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