Banca de DEFESA: MILTON GOMES DE SOUZA NETTO

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
DISCENTE : MILTON GOMES DE SOUZA NETTO
DATA : 28/10/2016
HORA: 14:30
LOCAL: Auditório do CCET
TÍTULO:

Astrophysics noise's classification in the presence of a planetary transit

PALAVRAS-CHAVES:

simulator of astrophysical correlated noise, time series, fractional Brownian motion, Hurst exponente, planetary transit.

PÁGINAS: 110
GRANDE ÁREA: Ciências Exatas e da Terra
ÁREA: Física
RESUMO:

Motivated by the growing number of missions and data in the exoplanet field and the shortage of mathematical models that use non-Gaussian and correlated noise in the photometry data, we analyze the change of the statistical parameter Hurst exponent, H, in time series of a variety types of astrophysical noise with and without the presence of a planetary transit. In addition, we determined the value of the Hurst exponent for two light curves from the public database of the CoRoT mission. To estimate the value of H we used two methods, the rescaled range analysis R/S and the fast Fourier transform, fft. To do this, we developed an astrophysical noise simulator, generating time series of several types of noises and estimate the value of H for all of time series. After, we generated a synthetic planetary transit and insert in the noise background and then recalculate the value of H. We note that the presence of planetary transit change significantly the value of the Hurst exponent, and the method of R/S analysis is more suitable than the Fourier Transform. We have found that the Hurst exponent can be a powerful discriminant to distinguish time series with different kind of variability, in particular the distinction between time series presenting a planetary transit. We also have estimated the Hurst exponent for 30 stars from public database of Kepler mission and relate to the orbital period of planets present in these systems.

MEMBROS DA BANCA:
Presidente - 1724218 - DANIEL BRITO DE FREITAS
Interno - 346785 - JOSE RENAN DE MEDEIROS
Externo à Instituição - MARIA LIDUINA DAS CHAGAS - UNIFESSPA