4,000 light-years from Earth is a strange object. Astronomers aren't sure what it is after it was observed by radio telescopes. It's called a long period Transient.
Transients are objects in the sky that change over time. Fast Transients are things that emit a bright flash over a period of seconds or milliseconds. Transients such as supernovae grow to extreme brightness over days or months. Three times an hour, this new object is Transient. It is one of the most bright radio objects in the sky, with its flash lasting anywhere from half a second to nearly a minute. It is so unusual because of its long period and extreme brightness.
One idea is that the object is a hypothetical object. Magnetars have stronger magnetic fields than pulsars. Magnetars have strong magnetic fields that can interact with ionized gas in a way that causes them to slow down. This would make it a kind of slow rotating pulsar. Astronomers thought that the ultra-long period magnetars wouldn't be nearly as bright. It isn't clear how a white dwarf could become so bright.
We know the object has a magnetic field. The radio light we see is very bright. The charged particles interact with a strong magnetic field. The Transient can be a standard effect. The rotation of the latinos sweeps a beam of intense radio light across the sky. We see a radio flash when the beam sweeps our way, like the flash of a lighthouse. The object would flash about every 18 minutes, but only for a few hours. During their observation runs, the team saw the object shift between active and quiet periods. There are strange things happening.
The most exciting idea is that the Transient object is something we don't expect. A black hole, or a quark star. It is difficult to narrow down the possibilities with only one example. The team is looking for similar objects in order to solve the mystery they never expected to find.
Nature 601: 526-530 is a reference to the article "A Radio Transit with Unusually Slow Periodic Emission".
