NGC 7635

The Bubble Nebula (NGC 7635) is a vast cloud of gas and dust located approximately 7,100 light-years from Earth in the constellation Cassiopeia. At its heart is BD +60°2522 (SAO 20575), a blue-white star roughly 45 times more massive than the Sun. The star generates an extraordinarily powerful stellar wind that sweeps up surrounding interstellar gas and dust, sculpting the nebula’s distinctive bubble-shaped shell. As the expanding shell encounters denser regions of cold gas on one side, its shape becomes distorted, causing the central star to appear strikingly off-center.