One of the idiosyncrasies of our sun, aside from the fact that it supports life on its third planet, is that while the corona (the wispy outer layer of gas) registers millions of degrees, its surface only hovers at around 6000ºC.
Between the two layers, the chromosphere clocks in at around 4000ºC. Both chromosphere and corona are visible during a solar eclipse, and scientists have speculated on the temperature difference for many years. Most believe it is related to the sun's magnetic fields and solar storms.
Now, using far-infrared light, the European Space Agency's Herschel space observatory has detected the same phenomenon in one of three stars in the Alpha Centauri system.
Proxima Centauri, a red dwarf planet, is the closest at 4.24 light years away; Alpha Centauri AB is a double star system at 4.37. While Alpha Centauri B has been in the news recently after the discovery of an earth-mass planet around it, Discovery News reports, Alpha Centauri A is the cosmic entity of interest to most scientists.
This star is "almost a twin to the Sun in mass, temperature, chemical composition and age," which makes it perfect for comparisons to the other two stars in its immediate neighborhood. With the discovery that it has a low-temperature layer that mirrors the one on our sun, scientists now have another sample to study as they try to decipher this occurrence.
"The study of these structures has been limited to the Sun until now, but we clearly see the signature of a similar temperature inversion layer at Alpha Centauri A," René Liseau of the Onsala Space Observatory in Sweden, and the paper's lead author, told Discovery News.
Alpha Centauri Bb is the closest exoplanet to earth — it has 113 percent of our planet's mass and orbits at a distance of 6 million kilometers from Alpha Centauri B, only 4 percent of earth's distance to the sun.
