Home
VISPA
Contact
Staff
Research
Telescopes
Seminars
History
News
Meetings
Teaching
Links
Publications
Theses
Visitors
OJ 287

 
 

Solar mini-explosions

An international team of astronomers, including Silja Pohjolainen of Tuorla Observatory, have observed a type of explosion on the surface of the Sun called a coronal mass ejection (CME), which releases super-heated gases into space. The fact that the CME comes from a very small, rather than a quite large region on the Sun, has come as a surprise to astronomers.

The team, put together by Tuorla Observatory researcher Silja Pohjolainen and Lidia van Driel-Gesztelyi at Paris Observatory, included researchers from Argentina, Finland, France, Hungary and the United Kingdom. Silja Pohjolainen discovered the so called 'X-ray bright point' when working with archival data from the Metsähovi Radio Telescope, which has been used to monitor the Sun for many years.

Understanding the source of outbursts from the Sun such as this has not only academic but also very practical implications. The plasma clouds which are ejected consist of high energy particles which cause beautiful auroras, but can also lead to radio transmission disturbances, power blackouts, satellite damage and harm astronauts -- an area of research which has become known as space weather. Space weather researchers now know that they have to keep track of the behaviour of even the small regions on the Solar surface and not just the large ones!

The research has appeared in the journal Astronomy and Astrophysics, 434, 725.

More on the solar research group at Tuorla here.


Posted 30th May 2005.

An image of the Sun made with the Yohkoh satellite, which operates at X-ray wavelengths. The small central dot (marked by a square), is a region about the same size as the Earth. An outburst of plasma, called a coronal mass ejection (CME), has been detected from this region, an observation which came as quite a surprise to astronomers, as CMEs have always previously been linked to huge complexes of sunspots. How frequent such outbursts from small solar regions is still unclear, and is likely to be an important topic for future space missions.