Análise da variabilidade fotométrica de estrelas análogas ao sol observadas pela missão TESS

Abstract

The Transiting Exoplanet Survey Satellite (TESS) space mission is revolutionizing the search for exoplanets by using the planetary transit technique through photometric observations, which also reveal signs of stellar variability. Studying these variabilities in solar analog bodies is fundamentally important for understanding the stellar dynamics of targets that exhibit characteristics similar to the only known star that hosts a planet with life. From this perspective, we analyzed the photometric variability of solar analog stars. These stars were selected based on photometric and atmospheric parameters obtained from the Gaia DR3 catalog, following criteria requiring similarity to solar parameters. After selection, we identified 4,932 targets. For the study of photometric variability, we used low-cadence light curves with 2-minute exposure intervals, provided by the TESS mission. We applied the following statistical methods: Fast Fourier Transform (FFT), Lomb-Scargle periodogram, and wavelet map. At the end of the analysis, we obtained the following results: 329 targets with light curves showing rotation signals (corresponding to 6.67% of our sample), 288 targets with dubious period of rotation signatures (5.84%), 467 targets with ambiguous variability signatures (9.47%), 4 targets with typical pulsating star signals (0.10%), 22 targets belonging to eclipsing binary systems (0.43%), and 3,759 targets without detectable modulation, with their photometric signals classified as noisy (76.21%). Overall, we found solar analog stars rotating with periods ranging from 0.410 to 10.452 days, with an average value of 4.507 days, faster than the Sun, which has a rotation period of approximately 25 days at its equatorial region. Additionally, we recorded stellar flares in 76 targets from our sample, with energies ranging from 1032 to 1035 ergs.