<p>This is because your image is not in focus. So you’re seeing the shadow of the secondary mirror.</p>
<p>You should have a knob near the eyepiece, that you can turn to adjust focus. You need to turn it, one way or another, until the image is as small as possible and as bright as possible.</p>
<p>Good luck!</p>

CC BY-SA 4.0
2022-01-09T05:48:47.307Z
I am attempting to look at Jupiter and I am running into the issue that this individual was experiencing. You said to turn the focus knob until the image is as small and bright as possible. If I'm using a 10mm eye piece would this tiny spec of white light be Jupiter?
Keegan
CC BY-SA 4.0
2022-01-09T08:05:40.597Z
It could be—if it’s really bright, then it most likely is, as there’s nothing as bright around Jupiter. Do you know the focal length of your telescope? Divide it by 10 (from your eyepiece) and you’ll get the magnification. If it’s under ~100× then it’s normal that it’s small and that you can’t see much detail. You should still see two darker stripes (called “bands”), though, with at least 20×–30×…
Pierre Paquette
CC BY-SA 4.0
2021-05-05T23:30:03.050Z
2021-05-05T23:30:03.050Z
Pierre Paquette
<p>This is a heavily de-focused image (possibly taken through cloud looking at the orangeish &quot;glow&quot; to the right). The dark center of the &quot;donut&quot; is the shadow of the secondary mirror centered within the image/pupil coming from the primary mirror. The focus needs to be adjusted until the &quot;donut&quot; shrinks down to sharper points of light or a disc (depending on whether you are looking at a star or an extended object such as the Moon or a planet)</p>

CC BY-SA 4.0
2021-05-05T23:29:39.433Z
2021-05-05T23:29:39.433Z
astrosnapper
<p>I was looking through my telescope for the first time and came across this weird star. I think its a celestial donut but im not sure.</p>
<p><a href="https://i.sstatic.net/VTrkW.jpg" rel="noreferrer"><img src="https://i.sstatic.net/VTrkW.jpg" alt="enter image description here" /></a></p>

CC BY-SA 4.0
2021-05-06T02:14:18.403Z
See these donut-related questions and their answers: [What cluster of stars is this with a “dark donut” to one side?](https://astronomy.stackexchange.com/q/33539,) and [Jupiter with a mobile phone and Celestron Astro FI 102mm Maksutov](https://astronomy.stackexchange.com/q/38278), and [Help identify a bright and round object photographed through a telescope](https://astronomy.stackexchange.com/q/34900), and [Did Hubble see a pair of UFOs? (Identify this artifact)](https://astronomy.stackexchange.com/q/33700)
uhoh
<star><amateur-observing>
What is that donut-shaped object I see in my telescope?
Mani S
# What is that donut-shaped object I see in my telescope?

(Asked by: username_0 on 2021-05-05)

I was looking through my telescope for the first time and came across this weird star. I think its a celestial donut but im not sure.

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

**Tags:** star, amateur-observing
> **Comments:**
> **username_1**: See these donut-related questions and their answers: [What cluster of stars is this with a “dark donut” to one side?](https://astronomy.stackexchange.com/q/33539,) and [Jupiter with a mobile phone and Celestron Astro FI 102mm Maksutov](https://astronomy.stackexchange.com/q/38278), and [Help identify a bright and round object photographed through a telescope](https://astronomy.stackexchange.com/q/34900), and [Did Hubble see a pair of UFOs? (Identify this artifact)](https://astronomy.stackexchange.com/q/33700)  

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## 2 answers

### Answer by username_2 on 2021-05-05. Score: 24

This is because your image is not in focus. So you’re seeing the shadow of the secondary mirror.

You should have a knob near the eyepiece, that you can turn to adjust focus. You need to turn it, one way or another, until the image is as small as possible and as bright as possible.

Good luck!

> **Comments:**
> **username_3**: I am attempting to look at Jupiter and I am running into the issue that this individual was experiencing. You said to turn the focus knob until the image is as small and bright as possible. If I'm using a 10mm eye piece would this tiny spec of white light be Jupiter?  
> **username_2**: It could be—if it’s really bright, then it most likely is, as there’s nothing as bright around Jupiter. Do you know the focal length of your telescope? Divide it by 10 (from your eyepiece) and you’ll get the magnification. If it’s under ~100× then it’s normal that it’s small and that you can’t see much detail. You should still see two darker stripes (called “bands”), though, with at least 20×–30×…  

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### Answer by username_4 on 2021-05-05. Score: 21

This is a heavily de-focused image (possibly taken through cloud looking at the orangeish "glow" to the right). The dark center of the "donut" is the shadow of the secondary mirror centered within the image/pupil coming from the primary mirror. The focus needs to be adjusted until the "donut" shrinks down to sharper points of light or a disc (depending on whether you are looking at a star or an extended object such as the Moon or a planet)


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