3C 397

3C 397 is also designated G41.1-0.3. The object is a supernova remnant in the Milky Way and a radio source listed in the Third Cambridge Catalogue. [NASA](https://www.nasa.gov/image-article/3c-397-an-unusual-galactic-supernova-remnant/)

X-ray studies show unusually high abundances of iron-group elements, including iron, nickel, manganese, and chromium. That chemical signature makes 3C 397 an important target for studying the physics of supernova explosions. [NASA](https://www.nasa.gov/image-article/3c-397-an-unusual-galactic-supernova-remnant/)

It has a strongly asymmetric, clumpy shape rather than a simple spherical shell. Multiwavelength studies also report especially hard X-ray emission toward its western lobe. [NASA](https://www.nasa.gov/image-article/3c-397-an-unusual-galactic-supernova-remnant/) [arXiv](https://arxiv.org/abs/astro-ph/0007372)

Its age is not settled, because different models produce different results. Published studies have estimated anything from roughly 1,000 years to about 5,300 years, so an approximate age is safer than one exact figure. [Oxford Academic](https://academic.oup.com/mnras/article/542/2/1125/8228480) [Chandra study](https://arxiv.org/abs/astro-ph/0407121)