We now turn to what we think is a magnetar – a super-dense, spinning neutron star – that is misplaced in a globular cluster. Recent observations of a fast radio burst in our galaxy seemed to indicate that these weird, brief bursts of radio light come from magnetars. That part is easy. All the physics makes sense.

The catch is that magnetars are supposed to be really, really young neutron stars – the results of the recent death of a fairly massive star – and this means we should only find magnetars and the fast radio bursts they create in places where big stars are actively dying. This is the same kind of place where smaller stars may still be forming and where, in general, we refer to the stars as young or short-lived.

Globular clusters, like the one this new fast radio burst and likely magnetar are linked to, well, they are places with only the oldest of old stars; places where the white dwarf stars are cooling, the neutron stars are slowing, and magnetars just shouldn’t happen.

And this raises the question: How is it that we are seeing fast radio bursts – repeating fast radio bursts – from a globular cluster? As discussed in a new paper in Nature led by Franz Kirsten, the answer likely involves stellar shenanigans.

It is possible to create stars that act like young stars and die like young stars by merging a couple of old stars into a single more massive star that goes through its own cycle of life and death, creating a new neutron star long after large star death should have ended. It is also possible that a white dwarf ate enough material off of a neighbor that it transformed into a brand new neutron star. According to Kirsten: This is a [magnetar] formation channel that has been predicted, but it’s hard to see. Nobody has actually seen such an event.

This is your regular reminder that the Universe is weird, anything that can happen probably will happen, and on a good day, we get to discover those weird things.

More Information

A fast radio burst’s unlikely source may be a cluster of old stars (Science News)

“A repeating fast radio burst source in a globular cluster,” F. Kirsten et al., 2022 February 23, Nature