NGC 2359 is the catalog designation for Thor's Helmet, an emission nebula approximately 15,000 light-years away in the constellation Canis Major. This nebula is shaped by the energetic winds from a central Wolf-Rayet star, creating a complex structure of glowing gas and dust.
Source: apod.nasa.gov
26/08/1996

What's a Wolf-Rayet star, and how did it create that spherical bubble and sweeping arc? A Wolf-Rayet star is a star that originated with a mass over 40 times that of our Sun. An extremely hot, luminous star, it has since expelled shells of material through its strong stellar wind which could account for the bubble shaped nebula that surrounds it. But astronomers are unsure how the central Wolf-Rayet created both the bubble and the arc seen above, and even whether it acted alone in doing so. Together, this bubble and the arc are known as NGC 2359.