Banca de DEFESA: CAMILLA BALLIANA DE SOUZA MARQUES

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : CAMILLA BALLIANA DE SOUZA MARQUES
DATE: 04/08/2026
TIME: 14:30
LOCAL: remoto
TITLE:

Population Characterization of Photometric Variability and Rotational Properties in TESS Objects of Interest (TOIs)

KEY WORDS:

Stellar variability; Stellar rotation; Population characterization; TOIs; TESS; Gaia DR3

PAGES: 106
BIG AREA: Ciências Exatas e da Terra
AREA: Astronomia
SUMMARY:

Stellar photometric variability is one of the richest observational signatures for understanding stellar internal structure, magnetic activity, and the habitability of planetary systems. With the advent of the TESS mission (Transiting Exoplanet Survey Satellite), the acquisition of high-precision light curves on a large scale has enabled the demographic analysis of these phenomena. In this context, this work presents a population characterization of photometric variability and rotational properties in a large sample of 7821 TESS Objects of Interest (TOIs), representing a significant statistical expansion compared to previous studies limited to 1000 targets. To diagnose variability and determine the rotation periods of this new sample, we used a multi-method approach for time-series analysis based on the Fourier Transform (FT), Lomb-Scargle (LS), and Wavelet Transform (WT), combined with a rigorous visual inspection. Additionally, the photometric data were cross-matched with the Gaia DR3 astrometric catalog, using the RUWE (Renormalized Unit Weight Error) parameter to identify possible contamination by unresolved binary systems in the sample. Our analysis revealed 568 targets (10.0% of the sample) with clear rotation signatures, with periods ranging from 0.7 to 13 days, 77 stars (1.3%) with pulsation signatures, 97 binary or multiple systems (1.6%), and 319 stars (5.5%) with ambiguous variability. For 3897 TOIs (67.9%), the light curves exhibited predominantly noisy behavior, indicative of low-amplitude variability. In addition, 140 stars with potential stellar flare events were identified, a phenomenon relevant to studies of planetary habitability, since such events may influence the atmospheres of nearby planets and their conditions for maintaining biological activity. The results obtained provide a robust catalog and an important statistical basis for studies of stellar rotation dynamics, star-planet interactions, and the physical characterization of stars hosting exoplanet candidates.

COMMITTEE MEMBERS:
Presidente - 1675216 - BRUNO LEONARDO CANTO MARTINS
Externo à Instituição - CARLOS EDUARDO FERREIRA LOPES
Interno - 346785 - JOSE RENAN DE MEDEIROS