I'm Being confused what is that light in the middle of milky way galaxy?

Image is from Charting the Milky Way From the Inside Out

The text with the image explains a lot about the spiral arms and the location of the Earth, but the central bright area isn't explained in great depth.

NASA: Charting the Milky Way From the Inside Out

  • 4
    $\begingroup$ Note that the galaxy in the picture is not an actual image of the Milky Way. $\endgroup$
    – Alchimista
    Apr 16, 2019 at 6:53
  • 2
    $\begingroup$ The page linked describes it as an "annotated artists concept" $\endgroup$ Apr 16, 2019 at 8:08
  • $\begingroup$ If you follow the link on that page to the "Unannotated version", there's a description which explains that "The galaxy's two major arms (Scutum-Centaurus and Perseus) can be seen attached to the ends of a thick central bar". When seen from within the disk (where we are), the inner, vertically thickened part of that bar is what has traditionally been called the "bulge" of the Milky Way (what Danish shows in their answer below). $\endgroup$ Apr 16, 2019 at 11:05

1 Answer 1


The galactic bulge is formed by tightly packed stars and interstellar dust Also most stars are in the direction towards the galactic center Thus it would appear brightest if it were viewed from outside the plane of the galaxy as this image is intended to show.

However, we don't see this from Earth, and the reason why is explained in Phys.org's Why can't we see the center of the Milky Way? explains why we don't see this at night.

A brief outline of what is described there is as follows:

When it is dark enough, and conditions are clear, the dusty ring of the Milky Way can certainly be discerned in the night sky. However, we can still only see about 6,000 light years into the disk with the naked eye, and relying on the visible spectrum. Here's a rundown on why that is.

  • Size and Structure
  • Low Surface Brightness
  • Dust and Gas
  • Limited Instrumentation

However we could see a bright spot if we were outside the Earth's atmosphere and could see in certain wavelengths of infrared. The article shows the following image from COBE

Milky Way in infrared. Credit: COBE

Milky Way in infrared. Credit: COBE Source

False-color image of the near-infrared sky as seen by the DIRBE. Data at 1.25, 2.2, and 3.5 µm wavelengths are represented respectively as blue, green and red colors. The image is presented in Galactic coordinates, with the plane of the Milky Way Galaxy horizontal across the middle and the Galactic center at the center. The dominant sources of light at these wavelengths are stars within our Galaxy. The image shows both the thin disk and central bulge populations of stars in our spiral galaxy. Our Sun, much closer to us than any other star, lies in the disk (which is why the disk appears edge-on to us) at a distance of about 28,000 light years from the center. The image is redder in directions where there is more dust between the stars absorbing starlight from distant stars. This absorption is so strong at visible wavelengths that the central part of the Milky Way cannot be seen. DIRBE data will facilitate studies of the content, energetics and large scale structure of the Galaxy, as well as the nature and distribution of dust within the Solar System. The data also will be studied for evidence of a faint, uniform infrared background, the residual radiation from the first stars and galaxies formed following the Big Bang.

  • $\begingroup$ I added some additional information to your answer, I hope you don't mind! $\endgroup$
    – uhoh
    Apr 16, 2019 at 10:50

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .