Fast radio bursts are strange things, but they aren’t likely to be caused by aliens.
A Repeating Mystery
Just when you think you’ve got a mystery solved, new data revives the mystery again.
The Mystery Of Fast Radio Bursts
They aren’t local, they aren’t aliens, and they might help us understand dark matter.
That Escalated Quickly
Astronomers have observed a fast radio burst originating from 5.5 billion light years away.
A Distant Noise
A while back I wrote about a phenomena known as fast radio bursts (FRBs). These short bursts of radio energy have been a bit of a puzzle. On the one hand they they have all the appearance of being astronomical in nature. For one thing, the frequencies of the signal are spread out so that higher frequencies arrive before lower ones. This is known as dispersion, and is an indicator having traveled through the interstellar medium. On the other hand, the signals are unusually strong, and their short duration is similar to radio interference from sources on Earth. They’ve also only been detected at one radio telescope (the Parkes radio telescope in Australia). That is, until now.
Over the Limit
Neutron stars typically form when a large star dies in a supernova explosion. The outer layers of the star are cast outward to form a supernova remnant, while the core of the star collapses into a dense neutron star. What keeps a neutron star from collapsing under its own weight is the pressure of the neutrons pushing against each other, similar to the way electron pressure works in a white dwarf star. But there is a limit to how much weight the neutrons can counter, known as the Tolman-Oppenheimer-Volkoff (TOV) limit. This limit means that a neutron star can’t be more massive than about three solar masses. More than that, and it would collapse into a black hole.