Stellar Atmospheres in Solar like Stars at Millimeter and Sub-millimeter Wavelengths
The atmosphere of the Solar-like stars is composed of the photosphere, chromosphere, transition zone, and corona. The chromosphere is the layer where the temperature goes from 4000 K to 8000 K and is studied at ultraviolet, visible, infrared, millimeter and (sub)-millimeter wavelengths (Wedemeyer et al. 2016)1. The first chromospheric models were obtained thanks to the ultraviolet observations (Vernazza et al. 1981; Avrett & Loeser 2008)2 3. However, recent observations made with the Solar Submillimeter Telescope (SST) and the Atacama Large Millimeter / Submillimeter Array (ALMA) have shown that the chromosphere has lower temperatures than expected by ultraviolet models (Linsky 2017).