Featured Research

from universities, journals, and other organizations

Fast radio bursts might come from nearby stars

Date:
December 12, 2013
Source:
Harvard-Smithsonian Center for Astrophysics
Summary:
First discovered in 2007, "fast radio bursts" continue to defy explanation. These cosmic chirps last for only a thousandth of a second. The characteristics of the radio pulses suggested that they came from galaxies billions of light-years away. However, new work points to a much closer origin -- flaring stars within our own galaxy.

New research suggests that mysterious events known as fast radio bursts might come from nearby flaring stars, rather than more energetic events in the distant universe. This image of the Sun, from NASA's Solar Dynamics Observatory, shows a lower-energy example of the kind of event that could cause fast radio bursts.
Credit: NASA

First discovered in 2007, "fast radio bursts" continue to defy explanation. These cosmic chirps last for only a thousandth of a second. The characteristics of the radio pulses suggested that they came from galaxies billions of light-years away. However, new work points to a much closer origin -- flaring stars within our own galaxy.

"We propose that fast radio bursts aren't as exotic as astronomers first thought," says lead author Avi Loeb of the Harvard-Smithsonian Center for Astrophysics (CfA).

Fast radio bursts are both brief and bright, packing a lot of energy into a short time. Only six have been discovered to date, all of them in archival data. Each was detected only once, making follow-up studies difficult.

A detailed analysis of the bursts showed that the pulses passed through a large column of electrons on their way to Earth. If those electrons were spread out across intergalactic space, then the pulses must have crossed billions of light-years. As a result, they would have to come from extremely energetic events. Gamma-ray bursts don't produce the right radio frequencies, so astronomers looked to other extreme events like the collapse of a neutron star into a black hole.

Loeb and his colleagues reasoned that if the bursts came from a closer location, within the Milky Way galaxy, then they wouldn't require as much energy. The explanation could be more mundane.

Stellar flares fit the bill. Tightly packed electrons in the stellar corona would cause the same effect as the more diffuse intergalactic electrons.

Two types of stars are known to create radio bursts: young, low mass stars and solar-mass "contact" binaries which orbit so close that they share their outer, gaseous envelopes. Both types of star system would also fluctuate in brightness at optical wavelengths (i.e. visible light).

To test their theory Loeb and his colleagues searched the locations of three fast radio bursts to look for variable stars, using the telescopes at Tel-Aviv University's Wise Observatory, in Israel.

"It was straightforward to monitor these fields for several nights, to see if they showed anything unusual," says Dani Maoz of Tel Aviv University.

"We were surprised that, apparently, no one had done this before," adds Yossi Shvartzvald, a graduate student who led the observations.

They discovered a contact binary system in one location. The binary consists of two Sun-like stars orbiting each other every 7.8 hours. They are located about 2,600 light-years from Earth. Statistics of stars across the observed field of view show that there is less than a 5 percent chance that the binary star is in the right place by coincidence.

"Whenever we find a new class of sources, we debate whether they are close or far away," says Loeb. Gamma-ray bursts were initially thought to be coming from within the Milky Way; only later did astronomers learn they came from cosmological distances.

"Here we have exactly the opposite," explains Loeb. Fast radio bursts, initially thought to be distant, may actually originate from our own galaxy.

The study has been accepted for publication in the Monthly Notices of the Royal Astronomical Society.


Story Source:

The above story is based on materials provided by Harvard-Smithsonian Center for Astrophysics. Note: Materials may be edited for content and length.


Cite This Page:

Harvard-Smithsonian Center for Astrophysics. "Fast radio bursts might come from nearby stars." ScienceDaily. ScienceDaily, 12 December 2013. <www.sciencedaily.com/releases/2013/12/131212123400.htm>.
Harvard-Smithsonian Center for Astrophysics. (2013, December 12). Fast radio bursts might come from nearby stars. ScienceDaily. Retrieved July 25, 2014 from www.sciencedaily.com/releases/2013/12/131212123400.htm
Harvard-Smithsonian Center for Astrophysics. "Fast radio bursts might come from nearby stars." ScienceDaily. www.sciencedaily.com/releases/2013/12/131212123400.htm (accessed July 25, 2014).

Share This




More Space & Time News

Friday, July 25, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Space to Ground: Coming and Going

Space to Ground: Coming and Going

NASA (July 25, 2014) One station cargo ship leaves, another arrives, aquatic research and commercial spinoffs. Questions or comments? Use #spacetoground to talk to us. Video provided by NASA
Powered by NewsLook.com
Raw: ISS Cargo Ship Launches in Kazakhstan

Raw: ISS Cargo Ship Launches in Kazakhstan

AP (July 23, 2014) The Progress 56 cargo ship launched from the Baikonur Cosmodrome in Kazakhstan Wednesday. NASA says it will deliver cargo and crew supplies to the International Space Station. (July 23) Video provided by AP
Powered by NewsLook.com
Raw: Cargo Craft Undocks from Space Station

Raw: Cargo Craft Undocks from Space Station

AP (July 22, 2014) A Russian Soyuz cargo-carrying spacecraft undocked from the International Space Station on Monday. The craft is due to undergo about ten days of engineering tests before it burns up in the Earth's atmosphere. (July 22) Video provided by AP
Powered by NewsLook.com
NASA Ceremony Honors Moon Walker Neil Armstrong

NASA Ceremony Honors Moon Walker Neil Armstrong

AP (July 21, 2014) NASA honored one of its most famous astronauts Monday by renaming a historic building at the Kennedy Space Center in Florida. It now bears the name of Neil Armstrong, the first man to walk on the moon. (July 21) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

    Health News

      Environment News

        Technology News



          Save/Print:
          Share:

          Free Subscriptions


          Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

          Get Social & Mobile


          Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

          Have Feedback?


          Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
          Mobile: iPhone Android Web
          Follow: Facebook Twitter Google+
          Subscribe: RSS Feeds Email Newsletters
          Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins