The chromosphere of α Cen A as seen by the herschel space observatory

Paper in proceeding, 2014

© 11th Scientific Meeting of the Spanish Astronomical Society. All rights reserved. Chromospheres and coronae are common phenomena on solar-type stars. Understanding the heating of those layers requires the direct access to the relevant empirical data. In particular, the chromospheric temperature minimum, i.e. the region of the atmosphere where the temperature undergoes a reversal and starts increasing to reach values of the order of MK in the corona, can be observed directly in the far infrared and in the submillimetre spectral regime. In this paper we present the results of the observations obtained in those ranges of the solar twin α Cen A. Similar to the Sun, the far infrared emission of this star originates in the temperature minimum above the stellar photosphere. To our knowledge, this is the first time a temperature minimum has been directly measured on a main-sequence star other than the Sun. This contribution is a summary of the the results presented in “α Centauri in the far infrared. First measurements of the temperature minimum of a star other than the Sun” [9] based on results from the Herschel Open Time Key Project DUNES and APEX/LABOCA observations.