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 April 20, 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 April 20, 2014).

Share This



More Space & Time News

Sunday, April 20, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

SpaceX's Dragon Spacecraft Captured by International Space Station

SpaceX's Dragon Spacecraft Captured by International Space Station

Reuters - US Online Video (Apr. 20, 2014) SpaceX's unmanned Dragon spacecraft makes a scheduled Easter Sunday rendezvous with the International Space Station. Rough Cut (no reporter narration). Video provided by Reuters
Powered by NewsLook.com
Raw: Easter Morning Delivery for Space Station

Raw: Easter Morning Delivery for Space Station

AP (Apr. 20, 2014) Space station astronauts got a special Easter treat: a cargo ship full of supplies. The SpaceX company's cargo ship, Dragon, spent two days chasing the International Space Station following its launch from Cape Canaveral. (April 20) Video provided by AP
Powered by NewsLook.com
A Hoax? Cosmetics Company Wants To Brighten The Moon

A Hoax? Cosmetics Company Wants To Brighten The Moon

Newsy (Apr. 19, 2014) FOREO, a Swedish cosmetics company, says it wants to brighten the moon to lower electricity costs. Video provided by Newsy
Powered by NewsLook.com
Raw: Space X Launches to Space Station

Raw: Space X Launches to Space Station

AP (Apr. 18, 2014) On it's second attempt this week, The Space X company launched Friday from Cape Canaveral to ferry supplies to the International Space Station. (April 18) 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