NGC 7635 Bubble Nebula

The Bubble Nebula sits in Cassiopeia about 7000+ light years away.  The interesting story on this target though is the rare ‘Wolf Rayet’ star that is blowing its outer layers as it dies.  These outer layers of stellar wind travel at 4 million miles per hour and sweep up gas into what we see as this bubble shell.  There is said to be around 200-300 of these super massive stars (25-50 times the size of our sun) in our milky way and they burn through their hydrogen and show their heavier elements to us in light spectrums.

These big stars burn fast and hot and a million times brighter than our sun.  The Wolf Rayet star in this picture is the right twinkling star inside the bubble.  Soon this huge star will go supernova and thus turn into a black hole or neutron star.  Because the dying stars begin to behave more like fluid, they can form these non-round shapes, some areas denser than others, but still target has a very cool bubble appearance to it.

This image shows blue regions which are indicative of Oxygen rich regions, while the Hydrogen and Sulfur regions are rich in reds.  Hydrogen, while visible red, is tone mapped to green and thus the yellowish regions.  RGB data was mixed in for stars to give them slight color.  Typical narrowband imaging with Sii, Ha and Oiii will combined into a hubble palette and give purple tendencies to stars.   NGC 7654 is the star cluster up top of the image known as the Cassiopeia Salt and Pepper Cluster.  Toward the bottom is NGC 7538 known as the northern Lagoon Nebula.

NASA has some very interesting videos and information on their site here:  https://svs.gsfc.nasa.gov/12247