I have to admit that it’s the changing nature of stars that makes me love them. A massive star that starts its life ten times the size of the Sun can end its life as an object only two times the mass of the Sun and collapsed down to the radius of Manhattan. All that missing mass is still there, surrounding the stellar remnant as a large colorful marker, saying something interesting happened here.

The problem is, sometimes the leftover bits of one dead star superimpose themselves on the remnants of another dead star, and sometimes, we can’t tell if we’re seeing the chance alignment of two events or the stunning product of a single star putting on a show.

The object HESS J1857+026 was one of these “Is it one or two things aligned” curiosities in the sky. This single patch of sky is home to sources of gamma-ray and radio light and a young, off-center pulsar. When things don’t line up perfectly, it’s easier to believe they may not all be in one place and actually associated with each other.

To get to the bottom of this system, astronomers Alberto Petriella, Laura Duvidovich, and Elsa Giacani imaged the system in a new color – or at least a different shade of radio light. This new data allowed them to determine there is a hot bubble – likely from the original supernova – and the hot bubble is the source of the gamma-ray light, and the pulsar is inside that hot bubble. It is essentially a nesting doll of science. Not a well-stacked nesting doll, but there is a pulsar surrounded by a hot bubble surrounded by a nebula, all shining chaotically in the night, and that is kind of awesome.

More Information

Study sheds more light on the nature of HESS J1857+026 (Phys.org)

“Radio study of HESS J1857+026. Gamma-rays from a superbubble?“, Alberto Petriella, Laura Duvidovich, and Elsa Giacani, to be published in Astronomy & Astrophysics (preprint on arxiv.org)