Breakthrough Listen, an
international collaborative
project to look for signals from extraterrestrial civilizations, has
employed its high-precision instruments to look at a one of a kind astronomical
event, the fast radio burst (FRB) 121102.
FRBs are brief and extremely
energetic pulses of radio waves whose mysterious origin has puzzled
scientists for the last two years. FRB 121102 is even more special, as it’s the
only one that repeats itself. This characteristic has allowed for detailed
studies of the source, with Breakthrough Listen detecting 15 high-frequency pulses during
just two 30-minute scans of that patch of the sky. This suggests that it’s in a
more active state.
“Bursts from this source
have never been seen at this high a frequency,” Andrew Siemion, director of the
Berkeley SETI Research Center and of the Breakthrough Listen program, said in
a statement.
The project used the Green
Bank Telescope, which is capable of recording several gigahertz of
bandwidth at a time. This allowed the team to spot the emission at a higher
frequency. Over the five hours of observations, 400 terabytes of data
were collected, and the team is currently combing through it.
“As well as confirming that
the source is in a newly active state, the high resolution of the data obtained
by the Listen instrument will allow measurement of the properties of these
mysterious bursts at a higher precision than ever possible before,” said
Breakthrough Listen postdoctoral researcher Vishal Gajjar, who discovered the
increased activity.
The most likely explanation
for FRBs is transient events. Neutron star collisions, hypernovas, or other
dramatic explosions can explain the sudden, powerful, and extremely brief
emission of radio sources. But a repeating source like FRB 121102 requires a
different explanation. After its origin
was pinpointed to an irregular galaxy 2.4 billion light-years away,
researchers were able to unravel the mystery a bit more.
The host galaxy is small,
only a fifth of the Milky Way in diameter, but it is producing stars at an
incredible rate. The signal originates from a large stellar nursery,
so researchers proposed an extremely powerful magnetic
neutron star.