Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Major flares are predictable on far-away stars, analysis of radio observations reveals


For the first time, astronomers are able to predict when major flares--enormous explosions that shoot hot gases into space--will erupt on stars outside our solar system, according to research to be published in an upcoming issue of the Astrophysical Journal.

The research is based on data from the longest-running continuous radio survey of flares produced by two types of binary systems, each containing a pair of stars under the influence of each other’s gravity. Stars in both binary systems, located about 95 light years from our solar system, are like a younger version of our Sun. "Studying the flares on these stars can help us understand more about how life evolved on Earth because they indicate the kind of environment that was bombarding our planet during an earlier age," says Mercedes Richards, professor of astronomy and astrophysics at Penn State University and the leader of the survey team.

During their 5-year-long observations, the researchers used the Green Bank Interferometer in West Virginia to continuously monitor radio waves produced by flares on pairs of stars as they circle each other like partners in a dance, regularly eclipsing each other when viewed from Earth. They studied two systems of such stars, one known as "The Demon Star," or "Beta Persei," which is the brightest and closest eclipsing binary pair in the sky. It contains a hot, blue star along with a cool, orange-colored star that is like our Sun but a bit more active. The other system, known as "V711 Tauri" to indicate its location in the constellation Taurus, also contains relatively cool stars like our Sun, one orange-colored and the other slightly hotter and yellow-colored.

Cool, Sun-like stars have an outer convective zone that produces a magnetic field. The pattern of a star’s flares reveal how its magnetic field is changing. "We were trying to discover the magnetic cycle within these stars by detecting a pattern in their strongest flares," Richards explains. The strength of flares in a binary pair is related to the age and speed of rotation of the cooler star. "Because we discovered that these flares occur at regular intervals, we now can predict accurately when future flares will occur," she says.

Because the strength of the Sun’s magnetic activity is relatively weak, astronomers have needed to accumulate close to 100 years of observations in order to get enough data to determine the Sun’s cycle of flare strength. The binary stars the team studied are younger than our Sun and are spinning about 10 times faster, so their flares are about 10 times more powerful and the astronomers were able to discover their interval pattern much more quickly.

The team’s observations of these two objects lasted from January 1995 until October 2000, when the Green Bank Interferometer was shut down. "Our continuous monitoring demonstrated that Beta Per and V711 Tau have active cycles and inactive cycles," Richards says. "This fact would not have been established if the systems had only been monitored sporadically. We could never be absolutely sure that no flares occurred at certain times unless we were monitoring the system all the time."

Richards and her collaborators used two independent statistical techniques to find out how often radio flares occur in these systems. They found that flares occur every 50 to 120 days in both systems. The survey also suggested a longer cycle of flares that lasted more than 500 days, or 1.4 years, with a pattern of active flaring and then very little flaring activity, but this long-term cycle could not be confirmed by the statistical analysis because tthe survey was not long enough to yield results that reach the usual criterion for statistical significance.

When Richards divided the long-term flare cycle by the rotation period of the cool star, she realized that the flaring cycles in the two binary systems may be related to magnetic cycles like the 11-year sunspot cycle on the Sun. "Now that we have begun to understand more about the flaring cycles on other stars, we may be able to better understand flaring in general, including the 11-year cycle of flares from our Sun, which regularly disrupts communications satellites on Earth," Richards says.

In addition to Richards, the research team includes Elizabeth Waltman of the Naval Research Laboratory, Frank Ghigo of the National Radio Astronomy Observatory, and Donald Richards of Penn State.

Mercedes Richards: 814-865-0150,
Barbara Kennedy (PIO): 814-863-4682,


Continuous monitoring of radio flares requires the availability of a dedicated telescope like the Green Bank Interferometer--a facility of the National Science Foundation that was operated during the collection of these data by the National Radio Astronomy Observatory with funding from the United States Naval Observatory, the Naval Research Laboratory, the National Radio Astronomy Observatory, and NASA’s High Energy Astrophysics Program. The National Radio Astronomy Observatory is a facility of the National Science Foundation, operated under cooperative agreement by Associated Universities, Inc. Richards received funding for this research from the Air Force Office of Scientific Research, the National Science Foundation, and NASA.

Barbara K. Kennedy | EurekAlert!
Further information:

More articles from Physics and Astronomy:

nachricht Computer model predicts how fracturing metallic glass releases energy at the atomic level
20.07.2018 | American Institute of Physics

nachricht What happens when we heat the atomic lattice of a magnet all of a sudden?
18.07.2018 | Forschungsverbund Berlin

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Future electronic components to be printed like newspapers

A new manufacturing technique uses a process similar to newspaper printing to form smoother and more flexible metals for making ultrafast electronic devices.

The low-cost process, developed by Purdue University researchers, combines tools already used in industry for manufacturing metals on a large scale, but uses...

Im Focus: First evidence on the source of extragalactic particles

For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.

To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...

Im Focus: Magnetic vortices: Two independent magnetic skyrmion phases discovered in a single material

For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.

Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...

Im Focus: Breaking the bond: To take part or not?

Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.

A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...

Im Focus: New 2D Spectroscopy Methods

Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.

"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....

All Focus news of the innovation-report >>>



Industry & Economy
Event News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Conference on Laser Polishing – LaP: Fine Tuning for Surfaces

12.07.2018 | Event News

11th European Wood-based Panel Symposium 2018: Meeting point for the wood-based materials industry

03.07.2018 | Event News

Latest News

A smart safe rechargeable zinc ion battery based on sol-gel transition electrolytes

20.07.2018 | Power and Electrical Engineering

Reversing cause and effect is no trouble for quantum computers

20.07.2018 | Information Technology

Princeton-UPenn research team finds physics treasure hidden in a wallpaper pattern

20.07.2018 | Materials Sciences

Science & Research
Overview of more VideoLinks >>>