A model for the Sun
An international team of scientists led by the University of Göttingen has observed a Sun-like magnetic cycle on another planet for the first time. The Sun’s magnetic field drives the Sun’s spots and flares and fuels the Solar wind – a torrent of material that streams off our star into space.
The discovery is important not only for stellar physics, but also to understand and predict how the Sun affects the Earth and our technological society through its magnetic activity. The results were published in Astronomy & Astrophysics.
With the advent of dedicated instruments known as stellar spectropolarimeters roughly ten years ago, it became possible to map the magnetic fields of nearby Sun-like stars. Using this new technology at the Bernhard Lyot Telescope in the French Pyrenees, the scientists observed the star 61 Cyg A over a period of nine years. Lying in the northern constellation of Cygnus, 61 Cyg A is somewhat smaller and less massive than the Sun, and at a distance of just over eleven light years it is one of the Sun’s nearest neighbours.
The Sun’s activity varies over the course of a 22-year long magnetic cycle, with the polarity of its magnetic field flipping every eleven years. The frequency and strength of these activities wax and wane over the course of a cycle, with two active periods interspersed with more quiet ones. All in all, the variations are relatively small and slow – a stark contrast to the great bulk of known magnetically active stars that vary dramatically in brightness, release enormous flares and display much more complex long-term variability.
Although 61 Cyg A is a little dimmer and cooler than the Sun, the scientists were able to detect changes in its activity coinciding with polarity flips over a seven-year activity cycle, for a magnetic cycle of 14 years. They observed polarity changes every seven years and an increased complexity in its magnetic field when these flips were approached.
“Our findings could contribute greatly towards creating models of how the Sun and other stars generate magnetic fields. This will enable us to gain an understanding of this important process, which is thought to be operating inside all Sun-like stars, and to help us to further understand our own Sun,” explains Sudeshna Bodo Saikia, Ph.D. student at Göttingen University and lead author of the study. A better understanding of this process and of our Sun in general will increase our ability to predict the impact of the Sun’s activities on our technology on Earth and on orbiting satellites.
The Solar wind and coronal mass ejections can indeed have a huge impact on Earth. When these flows of plasma reach Earth, they not only produce the northern and southern lights, but they can also disturb radio communication and power grids at ground level, as well as damage satellites and even threaten astronauts in Earth orbit.
Original publication: Sudeshna Boro Saikia et al. A solar-like magnetic cycle on the mature K-dwarf 61 Cygni A (HD 201091). Astronomy & Astrophysics 2016. Doi: 10.1051/0004-6361/201628262.
Sudeshna Bodo Saikia
University of Göttingen
Faculty of Physics – Institute for Astrophysics
Friedrich-Hund-Platz 1, 37077 Göttingen, Germany
Phone +49 551 39-13286
Thomas Richter | idw - Informationsdienst Wissenschaft
Move over, lasers: Scientists can now create holograms from neutrons, too
21.10.2016 | National Institute of Standards and Technology (NIST)
Finding the lightest superdeformed triaxial atomic nucleus
20.10.2016 | The Henryk Niewodniczanski Institute of Nuclear Physics Polish Academy of Sciences
Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.
"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...
In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.
A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...
By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.
"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...
COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.
In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...
'Ferroelectric' materials can switch between different states of electrical polarization in response to an external electric field. This flexibility means they show promise for many applications, for example in electronic devices and computer memory. Current ferroelectric materials are highly valued for their thermal and chemical stability and rapid electro-mechanical responses, but creating a material that is scalable down to the tiny sizes needed for technologies like silicon-based semiconductors (Si-based CMOS) has proven challenging.
Now, Hiroshi Funakubo and co-workers at the Tokyo Institute of Technology, in collaboration with researchers across Japan, have conducted experiments to...
14.10.2016 | Event News
14.10.2016 | Event News
12.10.2016 | Event News
21.10.2016 | Health and Medicine
21.10.2016 | Information Technology
21.10.2016 | Materials Sciences