Last year, we made an intriguing discovery—a radio signal in space that switched on and off every 18 minutes.
, we made an intriguing discovery—a radio signal in space that switched on and off every 18 minutes.
Astronomers expect to see some repeating radio signals in space, but they usually blink on and off much more quickly. The most common repeating signals come from pulsars, rotating neutron stars that emit energetic beams like lighthouses, causing them to blink on and off as they rotate towards and away from the Earth.
Pulsars slow down as they get older, and their pulses become fainter, until eventually they stop producing radio waves altogether. Our unusually slow pulsar could best be explained as a magnetar—a pulsar with exceedingly complex and powerful magnetic fields that could generate radio waves for several months before stopping.
Unfortunately, we detected the source using data gathered in 2018. By the time we analyzed the data and discovered what we thought might be a magnetar it was 2020, and it was no longer producing radio waves. Without additional data, we were unable to test our magnetar theory.
So, we used the Murchison Widefield Array radio telescope in Western Australia to scan our Milky Way galaxy every three nights for several months.
We didn’t need to wait long. Almost as soon as we started looking, we found a new source, in a different part of the sky, this time repeating every 22 minutes.
