Astrophysics & Astrophotography

DEM L316

DEM L316 is a distinctive, peanut-shaped nebula in the Large Magellanic Cloud. Recent research indicates that it is two distinct gas and dust clouds formed by different types of supernova explosions that occurred a few tens of thousands of years ago. Observations by the Chandra X-ray observatory reveal that the chemical compositions of the two shells are very different. The data show that the smaller shell (lower left in this image) contains significantly more iron than the larger one. The high abundance of iron in the small bubble indicates that the gas is the product of a Type Ia supernova. This type of explosion is triggered by the infall of matter from a star onto a white dwarf. Since white dwarf stars are extremely old objects, the system must have been a few billion years old when this supernova explosion took place. By contrast, the larger, less iron-rich bubble is the result of a Type II supernova that was triggered by the collapse of a massive star (more than seven times the mass of our Sun) when it was only a few million years old. Since the two progenitor systems had vastly different ages when they went supernova, there is little chance they came from the same system. Therefore, while the detailed structure seen in the GMOS image makes it look like the two bubbles are colliding, they only seem to be close together in the sky because of a chance alignment in our line of sight. The Large Magellanic Cloud is a sister satellite galaxy to our Milky Way and lies about 160,000 light-years away in the direction of the constellation Dorado. The DEM L316 nebula is located within the LMC and its two bubbles extend over a distance of about 140 light-years (roughly 35 times larger than the distance between our Sun and its nearest stellar neighbor).