Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

UI astronomers capture first-of-kind image at distant star

14.01.2010
Two University of Iowa researchers have made the first direct radio image of a stellar coronal loop at a star, other than the sun, thereby providing scientists with information that may lead to a better understanding of how such phenomena as space weather affect the Earth.

Robert Mutel, professor in the University of Iowa College of Liberal Arts and Sciences Department of Physics and Astronomy, and his graduate student William Peterson of Marshalltown, Iowa, spearheaded the research, which included astronomers from New Mexico and Switzerland. They published their findings in the Jan. 14 issue of the Journal Nature.

Mutel said that the image of the coronal loop (roughly resembling a rainbow) was made of the star Algol, a well-known variable star in the constellation Perseus. Algol (Arabic for demon) is also know as the Demon Star and is one of the first eclipsing binary stars and variable stars to have been discovered. Its brightness as seen from Earth temporarily decreases roughly every 69 hours.

"We imaged the coronal loop using a global array of radio telescopes," Mutel said. "We also carefully compared radio and optical coordinates, so we know where the radio source was located with respect to the star."

"Earlier attempts to image stellar coronal loops in visible light resulted in fuzzy blobs, but we used a global array of radio telescopes to make a series of images over a six-month period. High resolution radio interferometery allows us to image features which would otherwise be undetectable."

The instrument Mutel and Peterson used is actually a combination of 13 radio telescopes linked by computer. They include the 10-telescope VLBA (Very Long Baseline Array) composed of telescopes in Mauna Kea, Hawaii, St. Croix in the Virgin Islands, and North Liberty, Iowa; a 100-meter instrument at the Max Planck Institute for Radio Astronomy near Bonn, Germany; the National Radio Astronomy Observatory (NRAO) at Green Bank, W. Va.; and the NRAO's Very Large Array (VLA) in New Mexico.

Despite the impressive coordination of telescopes dedicated to capturing information from Algol, making sense out of all the data is difficult. "Learning how to take radio data and turn it into an image is a challenge," Peterson said.

Interpreting the data is perhaps just as challenging. Mutel noted that the coronal loop at Algol is similar to those at the sun, but the magnetic field at Algol is about 1,000 times more powerful.

Peterson said that the larger-than-predicted size of the coronal loop is probably due to the tidal effects of the companion star distorting the loop and stretching it. Additionally, the companion star causes the coronal loop to continually face the companion star.

Mutel said that a better understanding of Algol's coronal loops might help us to better understand the sun, something that could benefit a wide range of human activities.

"We really need to understand our sun," he said. "The sun is close to us and can be studied, but it is only one star. By studying other stars, we will be able to put its behavior into a broader context.

"Coronal loops at the sun are associated with sunspots. Sunspots, in turn, are associated with space weather, a constant stream of charged particles flowing outward from the sun. The intensity of solar radiation can affect everything from communications systems that rely on satellites to the health of astronauts who must sometimes work in space."

Mutel said that future research likely will focus on obtaining coronal loop images at other stars.

"Perhaps we can work toward predictions of space weather. Maybe we can better understand the physics of space weather through a study of coronal loops," he said.

Gary Galluzzo | EurekAlert!
Further information:
http://www.uiowa.edu

More articles from Physics and Astronomy:

nachricht Astronomers release most complete ultraviolet-light survey of nearby galaxies
18.05.2018 | NASA/Goddard Space Flight Center

nachricht A quantum entanglement between two physically separated ultra-cold atomic clouds
17.05.2018 | University of the Basque Country

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: Explanation for puzzling quantum oscillations has been found

So-called quantum many-body scars allow quantum systems to stay out of equilibrium much longer, explaining experiment | Study published in Nature Physics

Recently, researchers from Harvard and MIT succeeded in trapping a record 53 atoms and individually controlling their quantum state, realizing what is called a...

Im Focus: Dozens of binaries from Milky Way's globular clusters could be detectable by LISA

Next-generation gravitational wave detector in space will complement LIGO on Earth

The historic first detection of gravitational waves from colliding black holes far outside our galaxy opened a new window to understanding the universe. A...

Im Focus: Entangled atoms shine in unison

A team led by Austrian experimental physicist Rainer Blatt has succeeded in characterizing the quantum entanglement of two spatially separated atoms by observing their light emission. This fundamental demonstration could lead to the development of highly sensitive optical gradiometers for the precise measurement of the gravitational field or the earth's magnetic field.

The age of quantum technology has long been heralded. Decades of research into the quantum world have led to the development of methods that make it possible...

Im Focus: Computer-Designed Customized Regenerative Heart Valves

Cardiovascular tissue engineering aims to treat heart disease with prostheses that grow and regenerate. Now, researchers from the University of Zurich, the Technical University Eindhoven and the Charité Berlin have successfully implanted regenerative heart valves, designed with the aid of computer simulations, into sheep for the first time.

Producing living tissue or organs based on human cells is one of the main research fields in regenerative medicine. Tissue engineering, which involves growing...

Im Focus: Light-induced superconductivity under high pressure

A team of scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg investigated optically-induced superconductivity in the alkali-doped fulleride K3C60under high external pressures. This study allowed, on one hand, to uniquely assess the nature of the transient state as a superconducting phase. In addition, it unveiled the possibility to induce superconductivity in K3C60 at temperatures far above the -170 degrees Celsius hypothesized previously, and rather all the way to room temperature. The paper by Cantaluppi et al has been published in Nature Physics.

Unlike ordinary metals, superconductors have the unique capability of transporting electrical currents without any loss. Nowadays, their technological...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Save the date: Forum European Neuroscience – 07-11 July 2018 in Berlin, Germany

02.05.2018 | Event News

Invitation to the upcoming "Current Topics in Bioinformatics: Big Data in Genomics and Medicine"

13.04.2018 | Event News

Unique scope of UV LED technologies and applications presented in Berlin: ICULTA-2018

12.04.2018 | Event News

 
Latest News

Supersonic waves may help electronics beat the heat

18.05.2018 | Power and Electrical Engineering

Keeping a Close Eye on Ice Loss

18.05.2018 | Information Technology

CrowdWater: An App for Flood Research

18.05.2018 | Information Technology

VideoLinks
Science & Research
Overview of more VideoLinks >>>