After more than a decade of patiently waiting and watching, astronomers have seen signs that one of the rarest stars known to science is waking up from its slumber.
It's called XTE J1810–197, and it's part of an exclusive club of weird stars – it's one of just four highly magnetic magnetars that have been found to emit radio waves.
At least it did, until a decade ago when those radio waves went quiet. Now it's stirring again, and astronomers have their telescopes at the ready to record.
That might not sound that exciting, but magnetars themselves are incredibly weird. They're essentially 'dead' stars, because for reasons we don't fully understand, they have insanely powerful magnetic fields.
To get into perspective these incredibly dense, collapsed stars can generate magnetic fields that are around 1
We currently know of 23 magnetars, but XTE J1810–197 is something else entirely. While magnetars all blast out high energy stuff, XTE J1810–197 and only three other stars we've found pulse out radio waves.
19659002] Until now.
Since December 8 last year, researchers from the University of Manchester and Max-Planck Institute for radio astronomy have been monitoring a fresh stream of radio emissions from the most unusual cosmic object.
Interestingly, the profile of this new rhythm of radio waves shows some pretty big differences since they were first noticed all those years ago.
"The pulse changes seen so far from the source have been significantly less dramatic, on timescales from hours to months, than seen in 2006," the research team report.
scale that might be caused by tiny shivers in the star's crust.
The thing we still do not know about lot of magnetars. They are the same way as your average neutron star, starting with the collapsing core of a massive, dying star squeezing atoms so their nuclei are pressed butt-to-cheek.
magnetic fields in the order of 10 ^ 15 gauss. By comparison, a typical fridge magnet is around 50 gauss, which is still 100 times stronger than our planet's magnetic field at the surface.
What causes such a powerful magnetism is a mystery star spinning at hundreds of thousands of times per second and turning into a pulsar. these samples.
If that's not intense enough, since their prediction in the late 80s, magnetars have become associated with strange, irregular bursts of gamma and X-ray radiation that repeat in some parts of the sky.
The going explanation for these massive magnetization of the earth's neutron-packed crust – the magnetar equivalent of an earthquake – its magnetic field into new alignments.
The weird thing about XTE J1810–197 is a year after it briefly shone in X -rays back in 2003, astronomers noticed it was sighing in pulses of far gentler radio waves. Initial observations it was spitting out low energy electromagnetic radiation once, about every five and a half seconds.
It was the first of just a handful of radio-emitting magnetars that have been discovered.
This exclusive Class of star blurs the lines between these magnetic samples and the variety of pulses, their own magnetic fields channeling beams of radiation that glow in radio waves that sweep across the cosmos as they spin.
Maybe all magnetars produce radio waves in similar ways and we only see them in a few?
Going on this new study, it's possible that tremors in the star's crust of packed neutrons don't only realign its powerful magnetic field, but directly contributing to a range of electromagnetic frequencies that include radio waves
The research is currently available on the pre-review site, arxiv.org, so as to create some discussion.
Another teams of astronomers recently used NASA's Deep Space Network to check out XTE J1810–197 and two of its radio magnetar cousins. They also happened to notice some odd variations in the radio wave emission.
Future observations might help whittle away speculations on what behind these pulses, and why they come and go as they do.
Now that one of the beasts is awake again, it might be more to say on the matter.