Canis Major–Thor’s Helmet Nebula

Discovered in 1975, Thor’s Helmet Nebula/NGC 2359, an emission nebula lies in the constellation of Canis Major (The Great Dog). Composed of cosmic dust and gas it is fashioned by the Wolf-Rayet star, an extremely hot/large, bright star near the core of Thor’s helmet, which arcs through the intergalactic cloud encompassing it.

 (Attribution: Jschulman555, CC BY-SA 4.0 <https://creativecommons.org/licenses/by-sa/4.0&gt;, via Wikimedia Commons Page URL: https://commons.wikimedia.org/wiki/File:NGC_2359,_Thor%27s_Helmet_(core).jpg )

At a distance in the region of 11.96 thousand light years Thor’s Helmet is believed to be 280,000 times more brilliant than Earth’s Sun and 16 times the mass of the Sun.

As its name suggests this nebula has the appearance of the helmet worn by the mythological Norse God of thunder and lightning – Thor, who also boasts a day named in his honour – Thursday. Even by Norse god standards Thor’s Helmet is impressively large in magnitude, spanning a distance of about 30 light-years and resembling an interstellar bubble. The wings wing-styled projections jutting from Thor’s Helmet, are multifaceted strand-like formations.

(Attribution: European Southern Observatory/B. Bailleul, CC BY 4.0, via Wikimedia Commons Page URL: https://commons.wikimedia.org/wiki/File:Eso1238a.jpg )

The interstellar bubble is formed by a stellar wind. And it’s interaction with the interstellar clouds of gas and dust in the region (Molecular clouds), trigger ionising radiation. This is responsible for the Thor’s Helmet nebula’s radiance. It is comparable in disposition to the Bubble Nebula, in the constellation of Cassiopeia.

It is anticipated that in the next few millennia the Wolf-Rayet star, star in the Thor’s Helmet Nebula’s heart will go “supernova” – (spectacular stellar explosion).

References:

Thor’s Helmet

https://www.skyatnightmagazine.com/astrophotography/nebulae/thors-helmet-nebula/

https://noirlab.edu/public/images/noaoann10014a/

https://science.nasa.gov/thors-helmet