Thursday, Mar 6, 2025

NGC 2359 – Thor's Helmet Nebula NGC 2359 (also known as Thor's Helmet Nebula and Gum 4) is an emission nebula located in the constellation of Canis Major. Difficult to spot it with binoculars, it is instead visible through Telescopes with apertures of at least 120mm in diameter, in which it appears as a spot in the shape of the letter Q. In photography, however, it appears a wonderful object. At the center of the nebula is a very hot Wolf-Rayet star, which illuminates it, exciting its hydrogen and ionizing it, this star is cataloged as WR 7, or HD 56925, and has a magnitude of 10.40, and would be the main responsible for the formation of the nebula, composed of gas expelled by the star itself. Other hypotheses to explain the arc-shaped jets observed in the cloud include that the central star about 7 million years ago was a red supergiant, whose motion in an eastward direction caused a shock wave when the strong stellar wind collided with the surrounding interstellar medium, which was very dense due to the presence of a molecular cloud, causing the visible structure; still other hypotheses mention other stars as responsible for the arc-shaped structure of the nebula.