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Dynamic contextualization of a be star sample observed by tess using spectroscopic analysis

Grant number: 20/04445-0
Support type:Scholarships in Brazil - Scientific Initiation
Effective date (Start): June 01, 2020
Effective date (End): December 31, 2020
Field of knowledge:Physical Sciences and Mathematics - Astronomy - Stellar Astrophysics
Principal Investigator:Alex Cavaliéri Carciofi
Grantee:Pedro Ticiani dos Santos
Home Institution: Instituto de Astronomia, Geofísica e Ciências Atmosféricas (IAG). Universidade de São Paulo (USP). São Paulo , SP, Brazil
Associated research grant:18/04055-8 - High precision spectroscopy: from the first stars to planets, AP.TEM

Abstract

Classical Be stars are fast rotating, non super-giant, B-type stars that have (or had at some moment) emission lines in their spectra. This emission feature is due to the reprocessing of ultraviolet light by a viscous decretion disk, ejected from the stellar equator by a still unknown mechanism that involves the near-critical rotation of the central star and maybe radial and non-radial pulsation modes. There are many ways of determining whether or not the disk exists. Continuum emission gives rise to a disk excess emission, as well as the presence of some key spectral lines, such as H-alpha, can show that the disk is present at a given moment. Furthermore, variability happens for most observed Be stars, because of how the phenomenon happens. The TESS satellite is revolutionizing many fields of astronomy by providing high-precision, high-cadence photometry of objects across the entire sky. More than 1300 known Be stars will be observed by TESS in its first two years of operation. The main goal of this project is to provide key anciliary information about those stars by searching online databases for available spectra on the TESS targets. This will provide key information about the dynamical status of the disk both before and after the TESS data. (AU)