I’m just going to start this segment with a quote from researcher Daniele Michilli: It was unusual. Not only was it very long, lasting about three seconds, but there were periodic peaks that were remarkably precise, emitting every fraction of a second — boom, boom, boom — like a heartbeat.”
Michilli is describing the radio signal of a mysterious object that was spotted by the CHIME radio array as it watched the sky for fast radio bursts (FRBs).
First discovered in 2007, fast radio bursts are sudden and bright radio signals. Often, they last only fractions of a second and never repeat. This lack of predictability and repeatability for the vast majority of these signals has left many astronomers scratching their heads as we try and figure out just what is going on.
Or perhaps what variety of things is going on.
And this brings us to that “boom boom boom” of a signal that caught Michilli’s attention. Cataloged as FRB 20191221A, this signal lasted three seconds, and within those three seconds, its intensity varied with a 0.2-second beat.
This signal stood out both for its duration and for its beating. Fast radio bursts normally only last a fraction of a second as they crackle off a pulse, and while a few have been found that have periods of outbursts and periods of quiet that are predictable, this was the first time a longer pulse made of faster beats has been found. Adding to the mystery, the signal appears to originate in a galaxy several billion light years away, which implies this is an extraordinarily bright source.
An extraordinarily bright and super weird source that has outburst only once that we caught.
This object is discussed in a new paper in Nature that is presented by the CHIME Fast Radio Burst Collaboration. The paper suggests the source is some sort of a neutron star, like a pulsar, that for those three seconds was extraordinarily bright.
Last night on Facebook, I saw prominent astronomers doing the astronomer equivalent of “Hey, come look at this weird thing. Can’t quite tell what it is, but isn’t it cool?” Researchers around the world are now really hoping that patch of the sky goes “boom boom boom” again when our telescopes are looking. It may never happen. This may be a mystery for the ages; a mystery that, for three seconds, was the rhythm of the night.
McGill press release
MIT press release
“Sub-second periodicity in a fast radio burst,” The CHIME/FRB Collabortion et al., 2022 July 13, Nature