<p>Is this a photo from the Digitized Sky Survey (DSS)? If so, I have also seen these, but they are not true stars most of the time. They  are mostly "artifacts" left over from stacking or imaging.</p>

CC BY-SA 3.0
2017-06-27T13:39:23.940Z
2017-06-27T13:39:23.940Z
cnmcferren
<p>It is a bright star. You can see the "diffraction spikes" that are the signature of a point-like object.</p>

<p>The star will be in our Galaxy, so is certainly closer than the galaxy in the image. However, this is not why it appears to be big.</p>

<p>The image appears big because the starlight will be spread by the telescope objects over a finite area - the point spread function. In addition, when a star is very bright, the central CCD pixels saturate and charge can spill into adjacent pixels. Even if that were not the case, there is enough light in the "wings" of the point spread function to produce a large image.</p>

CC BY-SA 3.0
2017-06-24T17:40:37.800Z
But isn't the star 'very bright' to the detector optics because, in part, to its distance?  So distance is partly why star appears so big.
Natsfan
CC BY-SA 3.0
2017-06-24T18:59:33.710Z
@john Many of the "smaller" stars in the image will be closer. The star image is big because it is bright, and the imaging is not perfect.
ProfRob
CC BY-SA 3.0
2017-06-24T17:11:07.633Z
2017-06-24T17:11:07.633Z
ProfRob
<p><a href="https://i.sstatic.net/GMOSk.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/GMOSk.jpg" alt="enter image description here"></a></p>

<p>I was helping classify galaxies at <a href="https://www.galaxyzoo.org/" rel="nofollow noreferrer">Galaxy Zoo</a> when I came across this picture of a galaxy. The dull red body looks huge compared to the galaxy. Is it because it is closer to the earth? It would be interesting to know what is going on here.</p>

<galaxy>
Is the bright red body a star?
user1098
# Is the bright red body a star?

(Asked by: username_0 on 2017-06-24)

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

I was helping classify galaxies at [Galaxy Zoo](https://www.galaxyzoo.org/) when I came across this picture of a galaxy. The dull red body looks huge compared to the galaxy. Is it because it is closer to the earth? It would be interesting to know what is going on here.

**Tags:** galaxy


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## 2 answers

### Answer by username_2 on 2017-06-24. Score: 5 | Accepted answer

It is a bright star. You can see the "diffraction spikes" that are the signature of a point-like object.

The star will be in our Galaxy, so is certainly closer than the galaxy in the image. However, this is not why it appears to be big.

The image appears big because the starlight will be spread by the telescope objects over a finite area - the point spread function. In addition, when a star is very bright, the central CCD pixels saturate and charge can spill into adjacent pixels. Even if that were not the case, there is enough light in the "wings" of the point spread function to produce a large image.

> **Comments:**
> **username_3**: But isn't the star 'very bright' to the detector optics because, in part, to its distance?  So distance is partly why star appears so big.  
> **username_2**: @john Many of the "smaller" stars in the image will be closer. The star image is big because it is bright, and the imaging is not perfect.  

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### Answer by username_1 on 2017-06-27. Score: -3

Is this a photo from the Digitized Sky Survey (DSS)? If so, I have also seen these, but they are not true stars most of the time. They are mostly "artifacts" left over from stacking or imaging.


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