First-of-kind image of distant star captured

London, Jan 14 (ANI): Two researchers from the University of Iowa have succeeded in capturing the first ever direct radio image of a stellar coronal loop at a star, other than the sun.

The image is expected to be useful for understanding how the Earth is affected by phenomena like space weather.

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, led the research, which included astronomers from New Mexico and Switzerland.

The image of the coronal loop, which looks like a rainbow, was made of the star Algol, a familiar variable star in the constellation Perseus.

Mutel said: "We imaged the coronal loop using a global array of radio telescopes.

"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."

Mutel and Peterson used a combination of 13 radio telescopes linked by computer to capture the image.

Peterson said: "Learning how to take radio data and turn it into an image is a challenge."

However, interpreting the data is not easy.

Mutel said the coronal loop at Algol is resembles those at the sun, but the magnetic field at Algol is nearly 1,000 times more powerful.

According to Mutel, Algol's coronal loops could help in understanding the sun in a better way.

He said: "We really need to understand our sun...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 added: "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."

The study had been published in the Jan. 14 issue of the Journal Nature. (ANI)