Featured Research

from universities, journals, and other organizations

Light shone on star mystery: Why sun's corona is much hotter than its surface

Date:
February 4, 2013
Source:
Northumbria University
Summary:
Scientists have begun to unlock the mystery of why the outer edge of the Sun is much hotter than its surface for the first time.

Magnetic loop structures in the corona of the Sun. The loops highlight the Sun’s magnetic field and are visible because they support the dense, million degree gas typical of the corona.
Credit: Courtesy of the Science Team for NASA's Solar Dynamic Observatory

Scientists at Northumbria University have begun to unlock the mystery of why the outer edge of the Sun is much hotter than its surface for the first time.

A team led by Northumbria's Dr Richard Morton, and including researchers from the University of Sheffield and Queen's University Belfast, has used cutting-edge solar-imaging technology to observe the Sun's chromosphere -- a region of the Sun's atmosphere sandwiched between its surface (photosphere) and outer layer (corona) -- to an unprecedented level of detail.

For years astronomers have looked for the elusive mechanism that causes some stars to have a corona that is almost 200 times hotter than their photosphere, despite being further away from the heat source at the star's core. It is believed that the cause of the increased temperature is due to magnetohydrodynamic (MHD) waves that distribute the energy generated below the star's surface to the outer layers of the Sun's atmosphere

Now, for the first time, the team has examined the MHD waves using a UK-designed dedicated solar-imaging telescope known as Rapid Oscillations in the Solar Atmosphere, or ROSA, to observe the chromosphere with a high degree of clarity. The powerful tool enabled some of the highest resolution images of the chromosphere to be obtained, allowing the scientists to study the speed and power of the waves and then estimate the amount of energy that they transport.

Their calculations confirm that the MHD waves could be responsible for transporting energy from below the solar surface, out through the chromosphere, into the corona and leading to heating of the outer layers in excess of a million degrees.

Dr Morton said: "The Sun is our closest star and provides a unique opportunity to study the properties of stars in detail. Stars generate heat through thermonuclear reactions in their core and the temperature decreases towards the star's surface. However, a significant number of stars have higher temperatures at the outer edges of their atmospheres than they do on their surface.

"Our observations have permitted us to estimate the amount of energy transported by the magnetic waves, and these estimates reveal that the waves' energy meets the energy requirement for the unexplained temperature increase in the corona."

Northumbria University has launched a new Physics with Astrophysics degree, which will begin in September 2013. The course will teach aspects of modern astrophysics, including modules on the Sun and its properties.


Story Source:

The above story is based on materials provided by Northumbria University. Note: Materials may be edited for content and length.


Journal Reference:

  1. Richard J. Morton, Gary Verth, David B. Jess, David Kuridze, Michael S. Ruderman, Mihalis Mathioudakis, Robertus Erdιlyi. Observations of ubiquitous compressive waves in the Sun’s chromosphere. Nature Communications, 2012; 3: 1315 DOI: 10.1038/ncomms2324

Cite This Page:

Northumbria University. "Light shone on star mystery: Why sun's corona is much hotter than its surface." ScienceDaily. ScienceDaily, 4 February 2013. <www.sciencedaily.com/releases/2013/02/130204094608.htm>.
Northumbria University. (2013, February 4). Light shone on star mystery: Why sun's corona is much hotter than its surface. ScienceDaily. Retrieved April 17, 2014 from www.sciencedaily.com/releases/2013/02/130204094608.htm
Northumbria University. "Light shone on star mystery: Why sun's corona is much hotter than its surface." ScienceDaily. www.sciencedaily.com/releases/2013/02/130204094608.htm (accessed April 17, 2014).

Share This



More Space & Time News

Thursday, April 17, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

New Baby Moon 'Peggy' Spotted In Saturn's Rings

New Baby Moon 'Peggy' Spotted In Saturn's Rings

Newsy (Apr. 15, 2014) — A bump in the rings could be a half-mile-wide miniature moon. It was found by accident in Cassini probe images. Video provided by Newsy
Powered by NewsLook.com
Americas Glimpse Total Lunar Eclipse

Americas Glimpse Total Lunar Eclipse

AFP (Apr. 15, 2014) — A total lunar eclipse, the first since December 2011, took place early Tuesday morning with the Americas getting the best glimpse. Duration: 1:19 Video provided by AFP
Powered by NewsLook.com
NASA Showcases Lunar Eclipse

NASA Showcases Lunar Eclipse

AP (Apr. 15, 2014) — Star gazers in parts of North and South America got a rare treat early Tuesday morning - a total eclipse of the moon. (April 15) Video provided by AP
Powered by NewsLook.com
Spacecrafts Could Use Urine As Fuel Source

Spacecrafts Could Use Urine As Fuel Source

Newsy (Apr. 15, 2014) — New research says the urea from urine could be recycled for fuel. Urea is filtered out of wastewater when making drinking water. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins