This ad will auto close in 10 seconds

Star with cool atmospheric layer identified

Last Updated: Wednesday, February 20, 2013 - 19:04

Washington: ESA`s Herschel space observatory has detected a cool layer in the atmosphere of Alpha Centauri A, the first time this has been seen in a star beyond our own Sun.

The finding is not only important for understanding the Sun`s activity, but could also help in the quest to discover proto-planetary systems around other stars.

The Sun`s nearest neighbours are the three stars of the Alpha Centauri system.




One of the great curiosities in solar science is that the Sun`s wispy outer atmosphere - the corona - is heated to millions of degrees while the visible surface of the Sun is `only` about 6000 degree C. Even stranger, there is a temperature minimum of about 4000 degree C between the two layers, just a few hundred kilometres above the visible surface in the part of Sun`s atmosphere called the chromosphere.


The heating of the Sun`s atmosphere has been a conundrum for many years, but is likely to be related to the twisting and snapping of magnetic field lines sending energy rippling through the atmosphere and out into space - possibly in the direction of Earth - as solar storms. Why there is a temperature minimum has also long been of interest to solar scientists.




Understanding the temperature structure of stellar atmosphere s may also help to determine the presence of dusty planet-forming discs around other stars like the Sun.


First Published: Wednesday, February 20, 2013 - 19:04
comments powered by Disqus