Alien mystery: How did this mysterious 250 light-year-wide hole actually form?

This week’s space photo shows dark clouds of dust, glowing hydrogen gas and massive stars. Most notable: a gaping hole in the center of the nebula.

N44 is an emission nebula in the Large Magellanic Cloud. In this nebula we find several young and old star groups. The nebula is a thousand light-years long and – like the Large Magellanic Cloud – is about 170,000 light-years from Earth.

In the middle of mist a 250 light-year wide ‘hole’ can be seen† It’s a mystery why there aren’t shreds of gas and dust here. It is possible that stellar winds from the present massive stars have driven these gas clouds away, but this does not match measured wind speeds. Another possibility is that the nebula is surrounded by the expanding shells of ancient supernovae and thus created the cosmic void.

The emission nebula N44 is visible because the gas and dust present in the nebula is heated and ionized by nearby stars. In the case of ionization, an atom loses or gains an electron. Due to the heating, the gas and dust absorb energy. Then this energy is released again by emitting radiation. Many emission nebulae can also be found in our Milky Way, such as planetary nebulae (the Ring Nebula), supernova remnants (Crab Nebula) and H-11 areas†

Do you want to zoom in endlessly on N44? Then download the 288 megapixel photo with a size of 153 MB.