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When we look at the sky, and see the Milky Way, we mainly see a band, with no real center.

On a more accurate picture we can guess the center of the galaxy (see this picture), but we still don't see the center as some kind of big bright "star", like on this picture.

I know there is a lot of objects (stars, planets and dust) between us and the center of the galaxy. But stars are bright and they shouldn't "hide" the galaxy center's light since they shine too.

Why don't we see the galaxy center as a "night sun"?

How much dust is there so it's blocking the galaxy center's light?

Is it because of all Oort clouds of all solar systems that we don't see the galaxy center clearly?

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The main reason we don't see the bright center of our galaxy, which is composed of millions of stars, is dust. Visible light is absorbed and scattered by interstellar dust, but that doesn't mean we can't see it on other waves of the spectrum, for example, infrared light doesn't suffer as much because of the dust.

Notice on this image how bright the galaxy center looks on the infrared and the near-infrared pictures!:

Milky Way galaxy at different wavelengths

Image taken from the MultiwaveLength Milky Way website of NASA's Goddard Space Flight Center.

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  • $\begingroup$ But why it is not, because the possibility it is a black hole ? $\endgroup$
    – Ahmed Hamdy
    Commented Jan 6, 2014 at 14:39
  • $\begingroup$ @Ahmed Hamdy Excuse me if I don't understand but, why is it not what? $\endgroup$
    – Eduardo Serra
    Commented Jan 6, 2014 at 15:09
  • $\begingroup$ I meant, it might be because of the possibility of a black hole in the center of Galaxy? $\endgroup$
    – Ahmed Hamdy
    Commented Jan 6, 2014 at 15:28
  • $\begingroup$ @Ahmed Hamdy Yes, but my question is What might be because of the possibility? Are you saying that we don't see light because there's a black hole in the center? If that is the case, then no, it's not because of the black hole. The center of the milky way has a high density of stars, so it should be bright even if there was no black hole. Interstellar dust is what prevent us to see a bright center, regardless of the existence of a supermassive black hole in Sagittarius A* $\endgroup$
    – Eduardo Serra
    Commented Jan 6, 2014 at 15:51
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    $\begingroup$ @Ahmed Hamdy I'm not saying there's not a black hole, actually the existence of a supermassive black hole is almost certain. What I'm saying is that this black hole has nothing to do with the fact that we don't see the brightness of the center of our galaxy. Read this article by Cornell University's astronomy department to learn more about the balck hole in question and the effect it causes around it. $\endgroup$
    – Eduardo Serra
    Commented Jan 6, 2014 at 15:58
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You may like this youtube video: http://www.youtube.com/watch?v=duoHtJpo4GY

A detailed explanation can be found in Wikipedia: http://en.wikipedia.org/wiki/Sagittarius_A*

It's not the Oort clouds, neither stars nor planets, that make the center of the Milky Way invisible. It's 25 magnitudes of extinction by interstellar dust.

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