Record-Breaking Radio Waves from Ultra-Cool StarApril 30, 2012
Penn State University astronomers using the world's largest radio telescope, at Arecibo, Puerto Rico, have discovered flaring radio emissions from an ultra-cool star, not much warmer than the planet Jupiter, shattering the previous record for the lowest stellar temperature at which radio waves were detected.
The team from Penn State's Department of Astronomy and Astrophysics and the Center for Exoplanets and Habitable Worlds, led by Alex Wolszczan, the discoverer of the first planets ever found outside our solar system, has been using the giant 305-m (1000-ft) telescope to look for radio signals from a class of objects known as brown dwarfs. These objects are small, cold stars that bridge the gap between Jupiter-like giant planets and normal, more-massive, hydrogen-fusing stars. The astronomers hit the jackpot with a star named J1047+21, a brown dwarf 33.6 light years away in the constellation Leo, in a result that could boost the odds of discovering life elsewhere in the universe.
Matthew Route, a graduate student at Penn State and the lead author of the discovery paper, said, "This object is the coolest brown dwarf ever detected emitting radio waves -- it's half the temperature of the previous record holder, making it only about five times hotter than Jupiter."
The new radio-star is much smaller and colder than our Sun. With a surface temperature not much higher than that of a giant planet, and a size comparable to Jupiter's, it is scarcely visible in optical light. Yet the radio flares seen at Arecibo show it must have a strong magnetic field, implying that the same could be true of other similar stars.
Wolszczan, an Evan Pugh Professor of Astronomy and Astrophysics and the leader of the project, said, "This is a really exciting result. We hope that in the future we'll be able to detect yet colder brown dwarfs, and possibly even giant planets around other stars."
The possibility that young, hot planets around other stars could be detected in the same manner -- because they still maintain strong magnetic fields -- has implications for the chances of finding life elsewhere in our Milky Way Galaxy, Wolszczan explained. "The Earth's field protects life on its surface from harmful particles of the solar wind. Knowing whether planetary magnetic fields are common or not throughout the Galaxy will aid our efforts to understand chances that life may exist beyond the Solar System."
The discovery of radio signals from J1047+21 dramatically broadens the window through which astronomers can study the atmospheres and interiors of these tiny stars, using the radio detection of their magnetic fields as a tool. At the temperature of this brown dwarf, its atmosphere must be made of neutral gas, which would not give off radio signals like those seen. SO The energy to drive the signals is likely to come from magnetic fields deep inside the star, similar to the field that protects the Earth from dangerous high-energy particles. By monitoring the radio flares from J1047+21, astronomers will be able to tell how stable the magnetic field is over time, and, from flare duration, they can infer the size of the emitter itself. The results were published in the March 10 2012 edition of the Letters section of the Astrophysical Journal.
The Arecibo Observatory is operated by SRI International under a cooperative agreement with the National Science Foundation (AST-1100968), and in alliance with Ana G. Méndez-Universidad Metropolitana, and the Universities Space Research Association.
The Pennsylvania State University
Related Magnetic Fields Current Events and Magnetic Fields News Articles
Earth not due for a geomagnetic flip in the near future
The intensity of Earth's geomagnetic field has been dropping for the past 200 years, at a rate that some scientists suspect may cause the field to bottom out in 2,000 years, temporarily leaving the planet unprotected against damaging charged particles from the sun.
Strange quantum phenomenon achieved at room temperature in semiconductor wafers
Entanglement is one of the strangest phenomena predicted by quantum mechanics, the theory that underlies most of modern physics. It says that two particles can be so inextricably connected that the state of one particle can instantly influence the state of the other, no matter how far apart they are.
The route to high temperature superconductivity goes through the flat land
Superconductors are marvellous materials that are able to transport electric current and energy without dissipation.
HKUST scientists explain the theory behind Ising superconductivity
Superconductivity is a fascinating quantum phenomenon in which electrons form pairs and flow with zero resistance.
Electron partitioning process in graphene observed, a world first
Graphene, a single atomic layer of graphite with a carbon-layered structure, has been drawing much attention because of its abundant electronic properties and the possibilities of application due to its unique electronic structure.
Researcher's work offers more proof of Einstein's general theory of relativity
A Florida State University high-performance computing researcher has predicted a physical effect that would help physicists and astronomers provide fresh evidence of the correctness of Einstein's general theory of relativity.
Queen's University Belfast lead research milestone in predicting solar flares
An international team of researchers, led by Queen's University Belfast, has devised a high-precision method of examining magnetic fields in the Sun's atmosphere, representing a significant leap forward in the investigation of solar flares and potentially catastrophic 'space weather'.
Superconductor survives ultra-high magnetic field
Physicists from the universities of Groningen and Nijmegen (the Netherlands) and Hong Kong have discovered that transistors made of ultrathin layers molybdeendisulfide (MoS2) are not only superconducting at low temperatures but also stay superconducting in a high magnetic field.
Discovery of a new confinement state for plasma
The National Institutes of Natural Sciences National Institute for Fusion Science applied the "Momentary Heating Propagation Method" to the DIII-D tokamak device operated for the United States Office of Science, Department of Energy, by the General Atomics and made the important discovery of a new plasma confinement state.
Made to order: Researchers discover a new form of crystalline matter
Dust is everywhere: under the bed, on the stairs and even inside of plasmas. A team of researchers from Auburn University, the University of Iowa and the University of California, San Diego, using the new Magnetized Dusty Plasma Experiment (MDPX), the first U.S. experiment of its kind, recently discovered a new form of crystalline-like matter in strongly magnetized dusty plasma.
More Magnetic Fields Current Events and Magnetic Fields News Articles