NGC 6559 is a chaotic star-forming region of gas and dust located at a distance of about 5,000 light-years from Earth in the constellation of Sagittarius.
Visible above are red glowing emission nebulas of hydrogen, blue reflection nebulas of dust, dark absorption nebulas of dust, and the stars that formed from them. The first massive stars formed from the dense gas will emit energetic light and winds that erode, fragment, and sculpt the region. And then they explode. After tens of millions of years, the dust boils away, the gas gets swept away, and all that is left will be an open cluster of stars.
