N 44, Reindeer Nebula

N 44, Reindeer Nebula,

This composite image shows a superbubble in the Large Magellanic Cloud (LMC) located in the southern  constellation Dorado. The LMC is a small satellite galaxy of the Milky Way located about 160,000 light years from Earth. N 44 itself is about 1000 light years in size. The superbubble structure of N44 itself is shaped by the radiation pressure of a 40-star group located near its center; the stars are blue-white, very luminous, and incredibly powerful. The massive stars produce intense radiation, expel matter at high speeds, and race through their evolution to explode as supernovas. The winds and supernova shock waves carve out huge cavities called superbubbles in the surrounding gas.  Many new stars, some of them very massive, are forming in the star cluster NGC 1929, which is embedded in the nebula N44, so named because it is the 44th nebula in a catalog of such objects in the Magellanic Cloud. N44 is classified as an emission nebula because it contains large regions of  Hydrogen and Oxygen gas which are excited by the nearby stars. The Red color in the image comes from neutral hydrogen atoms, which emit the Hydrogen alpha line at a red wavelength of 656.2 nm. The blue color come from doubly ionized Oxygen which emits at 500.7nm. The image is a composite of a image made from the atomic Hydrogen and Oxygen emission and a true color R,G,B image. The stars come from the true color image.