Astronomers propose new explanation for these mysterious phenomena

Dec 12, 2013 14:54 GMT  ·  By

A group of astrophysicists at the Harvard-Smithsonian Center for Astrophysics (CfA) argues in an new study that so-called fast radio bursts (FRB) may in fact be produced by stellar flares within our galaxy. 

FRB were first discovered in 2007. These weird phenomena last for only a thousandth of a second, yet they pack a real punch. Scientists were only able to record six of these interesting radio pulses to date.

Previous analyses of fast radio bursts suggested that these flashes originated in distant galaxies, billions of years away from Earth. New data from the CfA team indicate a much closer origin for these events.

Studying FRB has been made difficult by the fact that these phenomena are not repeating. Most of the detections made thus far have been identified in archival data, so elaborating theories is very difficult.

Instead of focusing on complex explanations involving distant galaxies, the CfA team decided to take a more pragmatic approach, and analyzed fast radio bursts at face value. They determined that it is far more likely that these events originated in the Milky Way rather than anywhere else.

“We propose that fast radio bursts aren't as exotic as astronomers first thought,” says Avi Loeb, the leader of the research team, and the author of a new paper accepted for publication in the prestigious journal Monthly Notices of the Royal Astronomical Society.

The key to this study was an investigation of electrons. FRB data suggested that the radio waves had passed through a large column of diffuse cosmic electrons before reaching Earth. The CfA was able to show that tightly-packed electrons in stellar coronas would have the same influence on the radio bursts.

In order to test the new hypothesis, the team used the Wise Observatory at the Tel Aviv University, in Israel. “We were surprised that, apparently, no one had done this before,” says graduate student Yossi Shvartzvald, who conducted the observations.

“It was straightforward to monitor these fields for several nights, to see if they showed anything unusua,” adds TAU professor of astronomy Dani Maoz. The telescope was pointed at the locations of three FRB released over the past 6 years.

One of these locations, about 2,600 light-years from Earth, revealed a binary star system that may have been the source of a previous fast radio burst. The system is made up of two yellow dwarfs like the Sun, with an orbital period of 7.8 hours.

The CfA team determined that there is a less than 5 percent chance that the system lies at these exact coordinates by chance. Though this research provides an interesting alternative to other theories, more work is needed to fully understand FRB.