MESAS Meets KINICH-PAKAL: Measure and Modeling Main Sequence Stellar Atmospheres

The dominant emission mechanisms at millimeter/submillimeter remain largely unknown for most spectral types other than Solar analogues. This is due in part to the lack of data to inform stellar atmosphere models. In this work, we present a new methodology to fit the observed and synthetic spectrum of main-sequence stars through semiempirical models1. We use the Levenberg-Marquardt algorithm as a Nonlinear method, PakalMPI2 as the semiempirical model and the observations that are part of an ongoing observational campaign entitled Measuring the Emission of Stellar Atmospheres at Submillimeter/ Millimeter wavelengths3.

January 11, 2021 More
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).

December 31, 2020 More