Site Map
Follow us on Facebook Follow us on Twitter YouTube channel
Centro de Astrofísica da Universidade do Porto
Characterization of M-dwarf Stars using (N)IR wavelengths

Bárbara Rojas-Ayala

M dwarfs are the most numerous and long-lived stars and therefore can provide valuable information about the Galaxy and star/planet formation. However, their basic properties are tricky to measure using standard techniques for solar stars; they are intrinsically faint at visible wavelengths and their optical spectra exhibit strong molecular absorption.

I will present the metallicity and effective temperature techniques developed for M dwarf stars based on absorption features present in their modest resolution (R ~2700) K-band spectra and other ones based on their colors. These techniques have been calibrated using FGK+M dwarf pairs and synthetic atmosphere models. I will compare their results with other empirical measurements of low mass stars in the literature, and I will discuss the usefulness of the K-band methods for the characterization of exoplanet systems. Finally, I will show a new photometric technique based on IR/Optical magnitudes that provides [Fe/H] estimates accurate to RMSE ~0.12 dex for thousands of early M dwarfs in the SUPERBLINK survey.

31 October 2013, 13:30

Centro de Astrofísica
Rua das Estrelas
4150-762 Porto

Institute of Astrophysics and Space Sciences

Institute of Astrophysics and Space Sciences (IA) is a new but long anticipated research infrastructure with a national dimension. It embodies a bold but feasible vision for the development of Astronomy, Astrophysics and Space Sciences in Portugal, taking full advantage and fully realizing the potential created by the national membership of the European Space Agency (ESA) and the European Southern Observatory (ESO). IA resulted from the merging the two most prominent research units in the field in Portugal: the Centre for Astrophysics of the University of Porto (CAUP) and the Center for Astronomy and Astrophysics of the University of Lisbon (CAAUL). It currently hosts more than two-thirds of all active researchers working in Space Sciences in Portugal, and is responsible for an even greater fraction of the national productivity in international ISI journals in the area of Space Sciences. This is the scientific area with the highest relative impact factor (1.65 times above the international average) and the field with the highest average number of citations per article for Portugal.

Proceed on CAUP's website|Go to IA website