Featured Research

from universities, journals, and other organizations

Solar tsunami used to measure Sun's magnetic field

Date:
July 11, 2013
Source:
University College London
Summary:
A solar tsunami observed by NASA's Solar Dynamics Observatory and the Japanese Hinode spacecraft has been used to provide the first accurate estimates of the Sun's magnetic field.

An eruption on April 16, 2012 was captured here by NASA's Solar Dynamics Observatory in the 304 Angstrom wavelength, which is typically colored in red.
Credit: NASA/SDO/AIA

A solar tsunami observed by NASA's Solar Dynamics Observatory (SDO) and the Japanese Hinode spacecraft has been used to provide the first accurate estimates of the Sun's magnetic field.

Solar tsunamis are produced by enormous explosions in the Sun's atmosphere called coronal mass ejections (CMEs). As the CME travels out into space, the tsunami travels across the Sun at speeds of up to 1000 kilometres per second.

Similar to tsunamis on Earth, the shape of solar tsunamis is changed by the environment through which they move. Just as sound travels faster in water than in air, solar tsunamis have a higher speed in regions of stronger magnetic field. This unique feature allowed the team, led by researchers from UCL's Mullard Space Science Laboratory, to measure the Sun's magnetic field. The results are outlined in a paper soon to be published in the journal Solar Physics.

Dr David Long, UCL Mullard Space Science Laboratory, and lead author of the research, said: "We've demonstrated that the Sun's atmosphere has a magnetic field about ten times weaker than a normal fridge magnet."

Using data obtained using the Extreme ultraviolet Imaging Spectrometer (EIS), a UK-led instrument on the Japanese Hinode spacecraft, the team measured the density of the solar atmosphere through which the tsunami was travelling.

The combination of imaging and spectral observations provides a rare opportunity to examine the magnetic field which permeates the Sun's atmosphere.

Dr Long noted: "These are rare observations of a spectacular event that reveal some really interesting details about our nearest star."

Visible as loops and other structures in the Sun's atmosphere, the Sun's magnetic field is difficult to measure directly and usually has to be estimated using intensive computer simulations. The Hinode spacecraft has three highly sensitive telescopes, which use visible, X-ray and ultraviolet light to examine both slow and rapid changes in the magnetic field.

The instruments on Hinode act like a microscope to track how the magnetic field around sunspots is generated, shapes itself, and then fades away. These results show just how sensitive these instruments can be, measuring magnetic fields that were previously thought too weak to detect.

The explosions that produce solar tsunamis can send CMEs hurtling towards the Earth. Although protected by its own magnetic field, the Earth is vulnerable to these solar storms as they can adversely affect satellites and technological infrastructure.

Dr Long said: "As our dependency on technology increases, understanding how these eruptions occur and travel will greatly assist in protecting against solar activity."


Story Source:

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


Cite This Page:

University College London. "Solar tsunami used to measure Sun's magnetic field." ScienceDaily. ScienceDaily, 11 July 2013. <www.sciencedaily.com/releases/2013/07/130711113424.htm>.
University College London. (2013, July 11). Solar tsunami used to measure Sun's magnetic field. ScienceDaily. Retrieved July 23, 2014 from www.sciencedaily.com/releases/2013/07/130711113424.htm
University College London. "Solar tsunami used to measure Sun's magnetic field." ScienceDaily. www.sciencedaily.com/releases/2013/07/130711113424.htm (accessed July 23, 2014).

Share This




More Space & Time News

Wednesday, July 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Raw: Cargo Craft Undocks from Space Station

Raw: Cargo Craft Undocks from Space Station

AP (July 22, 2014) A Russian Soyuz cargo-carrying spacecraft undocked from the International Space Station on Monday. The craft is due to undergo about ten days of engineering tests before it burns up in the Earth's atmosphere. (July 22) Video provided by AP
Powered by NewsLook.com
NASA Ceremony Honors Moon Walker Neil Armstrong

NASA Ceremony Honors Moon Walker Neil Armstrong

AP (July 21, 2014) NASA honored one of its most famous astronauts Monday by renaming a historic building at the Kennedy Space Center in Florida. It now bears the name of Neil Armstrong, the first man to walk on the moon. (July 21) Video provided by AP
Powered by NewsLook.com
Neil Armstrong's Post-Apollo 11 Life

Neil Armstrong's Post-Apollo 11 Life

Newsy (July 19, 2014) Neil Armstrong gained international fame after becoming the first man to walk on the moon in 1969. But what was his life like after the historic trip? Video provided by Newsy
Powered by NewsLook.com
This Week @ NASA, July 18, 2014

This Week @ NASA, July 18, 2014

NASA (July 18, 2014) Apollo 11 yesterday, Next Giant Leap tomorrow, Science instruments for Europa mission, and more... Video provided by NASA
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