Scientists have discovered that the sun and its nearest twin star, Alpha Centauri , share an odd solar quirk: a puzzling cool layer in their wispy, hot atmospheres.
The different temperatures of the sun's layers have long intrigued solar scientists. The outer atmosphere, or corona, is millions of degrees hotter than the sun's surface, or photosphere, wheretemperatures are about 10,000 degrees Fahrenheit (5,537 degrees Celsius).
But the temperatures don't simply rise the further away you get from the surface. There is actually a cooler layer sandwiched between the photosphere and the corona called the chromosphere, where temperatures dip as low as 7,300 degrees F (4,000 degrees C).
Now scientists have found a similarly cool layer around Alpha Centauri A using the European Space Agency's Herschel space observatory to look at the nearby star in far-infrared light.
"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," study leader René Liseau of the Onsala Space Observatory in Sweden said in a statement. [Alpha Centauri Stars Explained (Infographic)]
Scientists believe the extreme heating of the sun's corona is likely related to the twisting of magnetic field lines that give rise to explosions known as solar flares. Studying Alpha Centauri A could help scientists better understand the atmospheric phenomenon, especially since the star is almost a twin to the Sun in mass, temperature, chemical composition and age.
"Detailed observations of this kind for a variety of stars might help us decipher the origin of such layers and the overall atmospheric heating puzzle," Liseau said.
The discovery may also help astronomers better estimate the amount of dust in the cold debris disks surrounding sun-like stars, the scientists said. The research is detailed in a recent edition of the journal Astronomy & Astrophysics.
The three stars of the Alpha Centauri system are the nearest to Earth beyond the sun. The two main stars are the binary pair Alpha Centauri A and Alpha Centauri B. They are about 4.37 light-years from Earth.
The third star, a faint red dwarf named Proxima Centauri, is the closest at just 4.22 light-years from Earth.
In 2012, astronomers announced the discovery of an Earth-size alien planet orbiting Alpha Centauri B.
Shkencetaret kane zbuluar qe Dielli dhe ylli me i afert binjak i tij, Alpha Centauri A, kane nje te perbashket te cuditshme: nje shtrese qe cuditerisht eshte e "ftohte" ne atmosferen e tyre shume te nxehte.Temperaturat e ndryshmte te shtresave te Diellit jane intriguar qe prej shume vitesh shkencetaret qe jane marre me studimin e tyre. Atmosfera me e jashtme, apo korona, eshte milion grade me e nxehte se siperfaqja e Diellit, apo fotosfera, ku temperaturat jane rreth 5.537 grade Celcius.Megjithate pjesa me e cuditshme eshte qe temperaturat nuk shtohen thjesht sa me shumi i largohesh siperfaqes se Diellit. Ne fakt ndodhet nje shtrase me e "ftohte" qe eshte ndermjet fotosferes dhe korones. Kjo shtrese ne mes quhet kromosfere, ku temperaturat jane te "uleta" dhe jane rreth 4.000 grade Celcius.Se pse ndodhet kjo shtrese dhe se si eshte formuar nuk eshte percaktuar ende.Megjithate, tani shkencetaret kane gjendur nje shtrese te ngjashme "te ftohte" tek Alpha Centauri A duke perdorur observatorin hapsinor European Space Agency's Herschel per te pare yllin e afert me drite infra te kuqe."Studimi i ketyre strukturave deri tani ka qene i limituar tek Dielli, por ne shohim qartesisht qe edhe tek Alpha Centauri A kemi nje ndryshim te ngjashem te habitshem temperature." - tha drejtuesi i studimit Rene Liseau i Observatorit te Hapesires ne Suedi.Shkencetaret besojne se nxehtesia ekstreme e korones se Diellit eshte me shume mundesi e lidhur me perdredhjen e linjave t efushave magnetike qe shkaktojne shperthime te njohura si fishekzjarret diellore. Studimi i Alpha Centauri A mund te ndihmoje shkencetaret te kuptojne me mire fenomenin atmosferik, vecanerisht per faktin qe ylli eshte pothuajse nje binjak i Diellit tone ne mase, temperature, kompozim kimik dhe moshe.
"Vezhgime te detajuara te ketij lloj varieteti yjesh mund te na ndihmojne te deshifrojme origjinen e ketyre shtesave dhe misterin e pergjithshem te nxehtesise atmosferike" - tha Liseau.
Zbulimi mund te ndihmoje astronomet te percaktojne me mire sasine e pluhurit ne disqet me copeza te ftohta qe rrethojne yjet e ngjashme me diellin.
Tre yjet ne sistemin Alpha Centauri jane me te afertit me Token pas Diellit. Dy yjet me kryesore jane cifti binar Alpha Centauri A dhe Alpha Centauri B. Ato jan erreth 4.37 vite drite larg Tokes.
Ylli i trete, nje xhuxh i zbehte i kuq i quajtur Proxima Centauri, eshte me i aferti dhe eshte vetem 4.22 vite drite larg Tokes.
Ne vitin 2012 astronomet deklaruan qe kishin zbuluar nje planet me madhesine e Tokes qe orbitonte rreth Alpha Centauri B.
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