4/21/2015

'Thor's Helmet' is a strikingly beautiful, messy nebula

thors-helmet-nebula.jpgWith a blue dome made from X-rays and wings created by superheated gas, nebula NGC 2359 is a fitting tribute to a certain Norse god.J.A. Toala & M.A. Guerrero (IAA-CSIC), Y.-H. Chu (UIUC/ASIAA), R.A. Gruendl (UIUC), S. Mazlin, J. Harvey, D. Verschatse & R. Gilbert (SSRO-South) and ESA
With "Avengers: Age of Ultron" set to debut in just a few days in the UK, perhaps the European Space Agency has caught a touch of superhero fever. Surely that must be why ESA just chose a nebula known as "Thor's Hammer" (or much more boringly as NGC 2359) as a featured space science image on its website.

The bright "bowl" of the helmet is actually a field of intense X-ray emissions, as captured by the super-sensitive cameras aboard ESA's XMM-Newton space observatory.
The X-rays are being emitted by a massive sun at the center of the nebula which is also called a Wolf-Rayette star. Wolf-Rayette stars have at least 20 times the mass of our own sun and "live fast and die hard," according to NASA. As this Wolf-Rayette star gets ready to go through its final death throes, it's ejecting a massive amount of material. According to the ESA, it loses the equivalent of one of our suns every 100,000 years through winds that reach speeds faster than 9,320 miles per hour.
The turbulence of that central star helps contribute the streaks of red and green seen to either side of the central blue dome, which look like the wings on Thor's helmet.
"Having such violent inhabitants has influenced NGC 2359's messy shape," says the ESA. "The nebula consists of a central bubble surrounded by a tangled web of gaseous filaments, thick channels of dark dust and bright outbursts, where material swept up by the stellar wind has collided with the surrounding gas and triggered rippling shock waves throughout the region."
In addition to showing the turbulence of the nebula, which is about 30 light-years across and about 15 thousand light-years from Earth, the image (which was first published here) also shows the temperatures present in its field. According to the ESA, the blue areas show temperatures "ranging from several million up to tens of millions of degrees."