WR stars are huge, perhaps as large as 20 solar masses. They lose mass as they evolve at an incredible rate, producing very strong solar winds. They are very hot with temperatures ranging from 30,000 to 200,000 Kelvin. There are about 500 of these stars cataloged in our Milky Way Galaxy. They give off a large amount of ultraviolet (UV) radiation that ionizes the surrounding nebula and makes it glow, allowing us to see it. Most of these WR stars are thought to progress to a supernova explosion.
The high contrast of narrowband filters were again used to bring out the interesting structure of RCW58 with long 30 minute individual exposures totaling 15.5 hours. A 5 nm H-a filter was color mapped to red/magenta and a 3 nm OIII filter was mapped to blue~green to achieve a "natural color". Star colors were added from shorter exposures using red, green and blue filters based upon a G2V white-point.