A bewilderingly powerful mystery object found in a nearby galaxy and only visible so far in millimeter radio wavelengths could be a brand new astrophysical object unlike anything astronomers have seen before…

…What we do know about Punctum is that based on how strongly polarized its millimeter light is, it must possess a highly structured magnetic field. And so, Shablovinskaia believes what we are seeing from Punctum is synchrotron radiation. Objects with strong polarization tend to be compact objects, because larger objects have messy magnetic fields that wash out any polarization.

Perhaps that synchrotron radiation is being powered by a magnetar, the team believes, which is a highly magnetic pulsar. However, while a magnetar’s ordered magnetic field fits the bill, magnetars (and regular pulsars for that matter) are much fainter at millimeter wavelengths than Punctum is.

Supernova remnants such as the Crab Nebula, which is the messy innards blasted into space of a star that exploded in 1054AD, are bright at millimeter wavelengths. The trouble is that supernova remnants are quite large — the Crab Nebula itself is about 11 light-years across — whereas Punctum is clearly a much smaller, compact object…