Twinkling star reveals ‘shocking’ secrets of plasma in our cosmic neighbourhood  Premium

Discovering plasma structures in the Local Bubble with powerful radio telescopes challenges existing theories of interstellar medium dynamics.

With the most powerful radio telescope in the southern hemisphere, we have observed a twinkling star and discovered an abundance of mysterious plasma structures in our cosmic neighbourhood.

The plasma structures we see are variations in density or turbulence, akin to interstellar cyclones stirred up by energetic events in the galaxy.

The study, published in Nature Astronomy, also describes the first measurements of plasma layers within an interstellar shock wave that surrounds a pulsar.

We now realise our local interstellar medium is filled with these structures and our findings also include a rare phenomenon that will challenge theories of pulsar shock waves.

Our observations honed in on the nearby fast-spinning pulsar, J0437-4715, which is 512 light-years away from the earth. A pulsar is a neutron star, a super-dense stellar remnant that produces beams of radio waves and an energetic “wind” of particles.

The pulsar and its wind move with supersonic speed through the interstellar medium – the stuff (gas, dust and plasma) between the stars. This creates a bow shock: a shock wave of heated gas that glows red.

The interstellar plasma is turbulent and scatters pulsar radio waves slightly away from a direct, straight line path. The scattered waves create a pattern of bright and dim patches that drifts over our radio telescopes as the earth, the pulsar and plasma all move through space.