Thursday, February 21, 2013

Alpha Centauri has a cool atmosphere

Something interesting has been discovered about our nearest celestial neighbour Alpha Centauri. Alpha Centauri A seems to have a cool atmosphere surrounding it, this is the first time anything like this has been seen beyond our own Sun.

Space Daily reports:

"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+ C. Even stranger, there is a temperature minimum of about 4000+ C between the two layers, just a few hundred kilometres above the visible surface in the part of Sun's atmosphere called the chromosphere.

Both layers can be seen during a total solar eclipse, when the Moon briefly blocks the bright face of the Sun: the chromosphere is a pink-red ring around the Sun, while the ghostly white plasma streamers of the corona extend out millions of kilometres.

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."

first an Earth mass planet around Alpha Centauri B and now this, even though this is a trinary system there seems to be a number of similarities to our own.

more here

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